Materials: stainless steel Device Full Length:S-45mm,M-55mm,L-60mm,XL-70mm Penis Tube Diameter:32mm/1.26inch When place your order,you need to select the cage style(S,M,L,XL) and the base ring combination. Base Ring Size:40mm/45mm/50mm/55mm(1.57inch/1.77inch/1.97inch/2.17inch) Base Ring Options you can choose: 40mm ring(1.57inch) 45mm ring(1.77inch) 50mm ring(1.97inch) 55mm ring(2.17inch) 40mm ring+45mm ring (1.57inch+1.77inch) 45mm ring+50mm ring(1.77inch+1.97inch) 50mm ring+55mm ring(1.97inch+2.17inch) 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. Curved oval base ring is available for this cage,check the last profile picture. If you want this kind of base ring with cage,please leave a note to speak your this demand. Otherwise cage with round ring is sent by default.