What are the most robust Thumb Cuffs?

Might anyone have a suggestion for the strongest and most quality-built thumbcuffs - either antique or contemporary? Many I have worked with quickly develop slipping or sticky rachets, or they just feel flimsy.

Thanks.

Not too sure how many thumbcuffs I have in my collection (unfortunately my record keeping is very poor and I have to admire collectors like Stan Willis who keep superb details of when they purchased an item, where it came from etc.). However I think the Tower Lyon thumbcuff of 1909 is the best, it has very positive strong springs on it and the fact that it 'concertinas' together with quite severe anti-slip notches all around its internal bows makes it very good.
Chris Gower

Might anyone have a suggestion for the strongest and most quality-built thumbcuffs - either antique or contemporary? Many I have worked with quickly develop slipping or sticky rachets, or they just feel flimsy.

Thanks.

I agree with Chris' evaluation. Of the 43 thumbcuffs in my collection, The Tower-Lyon is the most secure. Good luck in finding one. Most of the modern thumbcuffs are about the same as far as strength.
Stan