The Droptube case is one of the Precifluid accessories, designed to firmly lock the syringe on the gun and to make the connection between the piston and the pusher thanks to the magnetized ring in the DropTube. It exists in 3cc, 5cc, 10cc and 30cc.
References :
3CC : BDET003
5CC : BDET005
10CC : BDET010
30CC : BDET030