Ooze Resolution Res Caps were designed to take all the hassle and mess out of cleaning glass pieces. These water pipe end caps are made from super durable and stretchy silicone. This pack includes 4 green end caps, each in a different size. This pack is designed to fit glass water pipes of just about any size. Pour the Ooze Resolution cleaning gel inside the piece, seal off the openings with Res Caps, and shake to efficiently remove all the gunk and resin. The Res Caps can also be used to seal odors inside the bong and prevent spills while not in use, and during transport!