There is no escaping the Houdini chastity tube. It is made of a 1 1/2" stainless steel tube. It has a 1 1/2" stainless steel ring that locks around the testicles. The tube is locked to the ring with a brass padlock. (The brass padlock is included) Be sure to hold on to that key, because as I stated, there is no escaping the Houdini. It is light weight, and can be worn for long periods of time. It can not be detected under the clothing. You can take care of all bodily functions while wearing the Houdini. However, you will not be able to obtain an erection. No measurements are required for this device. It will fit 90% of the male population. Ships in 48 hrs.