I get all the Dr Kaplan tubes in a store in Philly for about $40 each. have 2" , 2.25", 2.5", 3" and 3.5" diameter tubes because of them being affordable. the 3" and 3.5" tubes hold both cock and balls and pull them down as they pump em full. so you get stretch with the fullness. but I agree..I want a monster tube or a bullmaker so my nuts themselves can pump even bigger, but they cost a fortune.