I purchased a 3″ x 8″ bare receiver and end cap. I set it up as a pumper (no liner, hose attachment on the end cap end). I first tried a 2 1/2 liner and used the double liner constrictor technique, then I tried a stiff but stretchable silicon cap from a penis pump that has a 1 1/4″ opening. Both options work well, but the liner is best for me. I use a Sunbeam mini heating pad wrapped around the receive to warm it. A little lube and suck in one ball and then the other and the ball stroking/sucking is mind blowing. The stroking & warm receiver relax and enlarge my balls to a bull ball low hanger size within a short time. The 3″ receiver give them plenty of room to grow and the pumping set up with the dbl constrictor keeps the receiver from popping off. There is no need to use any kind of straps to hold it on. I also sometimes use an elastic cord and loop it around the end of the receive and then to hook it to the foot board for an even stronger tugging on the exhale stroke. When it is time to remove it, detach the hose and since by nature one ball hangs lower, slip one ball out and then the other. The liner material stretches enough that it doesn’t hurt in anyway. BTW, I shave the bits and pieces which eliminates and hair pulling and make the testes more sensitive.