Yamaha Trombone Hand Strap

First, for €14, it is a cheap.

It is quite thin and stiff. The sticky patch is very secure. Although I can put them on an expensive trombone w F-attachment, I don't feel like I can trust it.
Putting it on a tenor trombone and it works fine, I use it because of my left wrist injury. The inner padding is not so soft, it is not comfy but not too distracting.

Overall, I would recommend spending 15€ more on other straps for your expensive instruments and hours of practice.