I've been into the leather scene now for about 8 years and interested in bondage for most of that time. The smell of leather has always done something to turn me on. And leather restraints with locks... well, that is guaranteed to drive me wild. I was at IML two years ago and found the most remarkable leather restraints. They are made out of high quality leather and really made well. The company that sells them is Extreme Restraints.
My favorite products that they sell are:
Leather Cuffs - These are very comfortable yet strong! Leather cuffs with leather lining and strong sticking. Locking roller buckles too.
These Leather thigh cuff restraints are really cool. Made just like the premium leather cuffs. They are really frustrating when you want to grab someone and make you pretty helpless. They can be hard to move very fast in them. These look really hot to me. They work best when you keep the wrist restraints locked to the thigh restraints.
These locking wrist to waist restraints are more practical leather restraints for keeping the hands from wandering. They are pretty sexy too and when wearing this leather wrist to waist restraints I can't prevent access to my nipples.