The fire polishing spacer allows you to consistently reposition the pipette within the filament. The T-shaped aluminum spacer has an adjustable setscrew.
The spacer/screw combination fits into the slot in the puller bar of the P-97 micropipette puller and fixes the puller bar position. You adjust the screw position to set the position of the puller bar (and thus the pipette tip). The more extended the screw is, the closer the pipette tip will be to the heating filament. When finished polishing the pipette, remove the spacer from the puller bar.