Materials: stainless steel Device Full Length:65mm/2.56inch Penis Tube Diameter:32mm/1.26inch Above sizes is fixed,what you can choose is the Base Ring Size. Base Ring Size:40mm/45mm/50mm(1.57inch/1.77inch/1.97inch) Base Ring Options you can choose: 40mm ring(1.57inch) 45mm ring(1.77inch) 50mm ring(1.97inch) 40mm ring+45mm ring (1.57inch+1.77inch) 45mm ring+50mm ring(1.77inch+1.97inch) The reason I offer 2 sizes base ring is to let customer can has 2 sizes ring to try,especially good for the beginers because they are not sure which size would fit them the best. The feature of this cage: it has 2 lock positions. As you can imagine,if the key holder can give you a key of the lock which near the pee hole,you can open the ending cover and pee without obstacle,that is the point of this design. Need other size base ring with this cage,select “customize size” to place order