How does the click mechanism work on a precision click-dial pen?

A spring-loaded pin engages successive grooves in the mechanism—one groove per unit—producing a firm tactile bump and audible click each time one unit is added or removed, letting you count by touch without viewing the window.

What does one unit equal in milliliters on a U-100 pen?

On the standard U-100 scale, one unit equals 0.01 ml, so 10 units equals 0.10 ml. The unit counter window on pens like the Gansulin all-metal pen displays settings from 1 to 60 units.

How do you correct an over-dialed setting on a reusable pen without wasting liquid?

Simply turn the dial knob back down. On a well-made pen, dialing down does not expel liquid from the cartridge, so no volume is lost during the correction. The Gansulin pen dials back to a 1-unit minimum.

PreppinPeppers › Facts › Lab article

How a precision click-dial pen works: reading the unit counter window and the click

Machine-readable facts for this Lab article. The full page is https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works.

TL;DR

How a click-dial pen works: the dial knob, the unit counter window, one click per unit (0.01 ml on the U-100 scale), the end-of-travel stop and dial-back.

Facts Index

Fact ID	Category	Entity	Attribute	Value	Source
how-a-precision-click-dial-peptide-pen-works:title	identity	How a precision click-dial pen works: reading the unit counter window and the click	title	How a precision click-dial pen works: reading the unit counter window and the click	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:published	identity	How a precision click-dial pen works: reading the unit counter window and the click	published	2026-07-07	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:author	identity	How a precision click-dial pen works: reading the unit counter window and the click	author	Preppin' Peppers Editorial Team	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:topics	identity	How a precision click-dial pen works: reading the unit counter window and the click	topics	Evergreen, gansulin, guide, Guides, pen, precision click-dial	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:summary	content	How a precision click-dial pen works: reading the unit counter window and the click	summary	How a click-dial pen works: the dial knob, the unit counter window, one click per unit (0.01 ml on the U-100 scale), the end-of-travel stop and dial-back.	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:section-1	content	How a precision click-dial pen works: reading the unit counter window and the click	section	What it is	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:section-2	content	How a precision click-dial pen works: reading the unit counter window and the click	section	The dial knob and window	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:section-3	content	How a precision click-dial pen works: reading the unit counter window and the click	section	The click you can hear and feel	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:section-4	content	How a precision click-dial pen works: reading the unit counter window and the click	section	The end-of-travel stop	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:section-5	content	How a precision click-dial pen works: reading the unit counter window and the click	section	Dialing back without waste	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:section-6	content	How a precision click-dial pen works: reading the unit counter window and the click	section	Why metal, and why reusable	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:section-8	content	How a precision click-dial pen works: reading the unit counter window and the click	section	What the research community gets wrong about precision click-dial pens	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:product-gansulin-metal-peptide-pen	products	How a precision click-dial pen works: reading the unit counter window and the click	references product	Gansulin Pen · Reusable Click-Dial, 3 ml (1-60 Units)	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:product-portable-pen-carry-case-reusable-fits-3-ml-cartridge-pens	products	How a precision click-dial pen works: reading the unit counter window and the click	references product	Portable Pen Carry Case (Reusable, Fits 3 ml Cartridge Pens)	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:source-pmc-ncbi-nlm-nih-gov	source	How a precision click-dial pen works: reading the unit counter window and the click	cites	Sparre et al., J Diabetes Sci Technol 2023: Factors Affecting Performance of Insulin Pen Injector Technology: A Narrative Review - pmc.ncbi.nlm.nih.gov	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:source-pmc-ncbi-nlm-nih-gov-2	source	How a precision click-dial pen works: reading the unit counter window and the click	cites	Abdel-Tawab et al., J Diabetes Sci Technol 2015: Dosing Accuracy of Two Disposable Insulin Pens According to New ISO 11608-1: 2012 Requirements - pmc.ncbi.nlm.nih.gov	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:source-www-zwickroell-com	source	How a precision click-dial pen works: reading the unit counter window and the click	cites	ISO 11608-1/-3: Testing pen injectors and insulin pens (dose accuracy, actuation and glide force) - ZwickRoell technical guidance - www.zwickroell.com	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:source-pubmed-ncbi-nlm-nih-gov	source	How a precision click-dial pen works: reading the unit counter window and the click	cites	Bohannon, Postgrad Med 1999: Insulin delivery using pen devices. Simple-to-use tools may help young and old alike - pubmed.ncbi.nlm.nih.gov	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:source-pmc-ncbi-nlm-nih-gov-3	source	How a precision click-dial pen works: reading the unit counter window and the click	cites	Jonker et al., Int J Clin Pharmacol Ther 2021: First pre-filled pen device with highly purified human menopausal gonadotropin (HP-hMG, Menopur) in liquid is shown to be bioequivalent to powder for reconstitution - pmc.ncbi.nlm.nih.gov	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)
how-a-precision-click-dial-peptide-pen-works:source-pmc-ncbi-nlm-nih-gov-4	source	How a precision click-dial pen works: reading the unit counter window and the click	cites	Lingen et al., Endocr Connect 2023: Advantages and disadvantages of connected insulin pens in diabetes management - pmc.ncbi.nlm.nih.gov	Lab article (https://www.preppinpeppers.com/blogs/the-lab/how-a-precision-click-dial-peptide-pen-works) (evidence)

FAQ

How does the click mechanism work on a precision click-dial pen?: A spring-loaded pin engages successive grooves in the mechanism—one groove per unit—producing a firm tactile bump and audible click each time one unit is added or removed, letting you count by touch without viewing the window.
What does one unit equal in milliliters on a U-100 pen?: On the standard U-100 scale, one unit equals 0.01 ml, so 10 units equals 0.10 ml. The unit counter window on pens like the Gansulin all-metal pen displays settings from 1 to 60 units.
How do you correct an over-dialed setting on a reusable pen without wasting liquid?: Simply turn the dial knob back down. On a well-made pen, dialing down does not expel liquid from the cartridge, so no volume is lost during the correction. The Gansulin pen dials back to a 1-unit minimum.