The Nanoliter injector is a micro-processor controlled injection system that uses direct piston displacement. The collet assembly (exploded view) is shown in the image below. The glass pipette fits into the white, plastic sleeve (spacer). When the collet is screwed in place securely, the black rubber washers are compressed and hold the glass firmly in place.
A side view of the assembled Nanoliter injector is shown below.
As the plunger is depressed, it pushes into the glass to expel the liquid in the pipette. Eventually, the diameter of the plunger matches that of the glass, and the plunger cannot expel any more liquid. If the plunger continues to press on the tip of the pipette, the pipette could crack or become dislodged from the plastic sleeve (spacer) inside the collet assembly. If that happens, the Nanoliter will begin to leak.