Tiniest harness I have found.  An Australian brand Dede loves.  This is the exact size Dede's dogs Faith and Saki wear.  12mm thickness and this size allows for small dogs to fit snug and have barely any room to escape.  Faith is a booker, so she needed to find a harness that would allow Faith to stay in when she sees something that freaks her out, this is the ONE.  Dede has it on very tight.  Dede also has a martingale collar for them so while walking either on harness or collar.  The collar tightens when the dog is leashed and trying to get away.  All harnesses allow for a dog to peel out, so be aware of that as you pick.  For small dogs to stay in their harness, Dede thinks this is the BEST brand!  12mm thickness. Neck 10"-15" and body 12"-17" All Sales Final.