I have owned a cb-3000 for a few months and recently received a 6000s. At first glance, the 6000s has a much nicer design for putting on. it feels much more secure and has not pinched me yet. The problem that I have is the lock that comes with it is so large and sits on top of the tube which causes it to clearly protrude and make a very large bulge in my pants. I have read that some people have just opted to use the plastic locks, and I have seen the tiny lock from lockeduplove.net, but I would prefer one with an actual key or at least had a space to put the key on a chain. My girl likes to have sex a lot, so she'll be taking me out of this thing on a fairly regular basis (weekends at the very least). I am just curious to know if anyone has found a tiny lock with a key, smaller than the one that comes with the 3000 or the 6000s. Much appreciate any help with this issue as I will probably be using the plastic locks and may be forced to purchase the lockeduplove version soon if i cannot find something that works.