The Ultimate Cartridge Optimizer
 
Sold 5 Spacers for $2.00

Maximize your yield with our universal injection pen spacers. Designed to eliminate the "dead space" at the bottom of standard cartridges, these spacers nudge the stopper higher so your pen can finish the job. 
 
After your cartridge is completely prepped, place the spacer at the bottom of your cartridge right on top of the Grey Rubber Stopper.  This will allow the plunger to push the Grey Rubber Stopper further up, making it easier to access the last remaining liquid in your cartridge.