A little while ago I found one on Ebay I knew it was a Knockoff but the price was worth a try. Its about the same length as a CB6K but If you are too small or large for a CB6K then it probably wont fit. I fit a CB6Ks (small) and I just fit into it and with a little water based lube (cannot fit in without it) The ring (Odd shape) goes on first and is very very comfortable. The tube slots in under the top of the ring and slides into place with a small notch sticking up with a hole for the lock to fit into. There is a cap that fits over the notch but the notch sticks up through a hole. Now you can put the lock through the hole and your done. My wife approved of the device and pink colour. The device did not stick into her if we slept in a spooning position due to its downward shape. PROs Its very comfortable and even sleeping in. Very little lube is needed (if any) on the rings. The knockoff has different colours available (I got pink) Its very discreet and points downwards. Its very light too. CONs There can be some edges of the device that needs sanding down. Not enough air holes for ventilation. Cant really shower with it. The notch hole is the weakest part. After 12 days Full Time wear I awoke to find the Notch hole had broken possibly due to a very long and strong night of erections pushing against it all night. Could it have been because it was a knockoff ??? or was it a design flaw. What i can tell you is it was very comfortable while it lasted. Knock off was €20 approx with multiple ring sizes 42mm 44mm 47mm Original as far as i know is €55 approx with multiple rings.