My wife and I purchased one of theese guys about 4 years ago and it is still going strong, she loves it.
It has a medium to large girth and strong vibrating tickler, the unit is quiet in operation and easy to clean, we still use petroleum jelly sometimes and there has been no degredation to the rabbit, so it must be a good quality silicone rubber.
It has a mild but pleasant odor when cleaned sort of berry, it is on it's third set of batteries. I hope this helps as I like to see a good product stand out. Jim.