- KJS Brass Design Premium Hand protector for 4/4 tuba; made of aluminum; protects the surface of the instrument and is a real eye-catcher at the same time; handmade; provided with a full-surface silicone insert; suitable for models with a bell circumference of 43-48cm at the thumb ring; the hand protector is placed at the narrowest point of the bell and then pushed up towards the bell until it is tight; thanks to the specially selected silicone insert, there are no traces of any kind on the instrument surface; once in place, the protector rest stays in place, but can be easily detached at any time; colour: black powder-coated; Made in Germany