The VacuGlide Stroker Cap & Nipple Valve cap enables the suction function on all of your VacuGlide tubes. 

It comes off by hard pulling and snaps into place. It is swappable to any of the different stroker tube sizes.

The silicone nipple is permanently affixed to the top of this cap, and it additionally comes with 1 grey silicone insert which helps regulate the pressure.