The Stubben Sweet Copper Angled Loose Ring Bit has a sweet copper alloy mouthpiece that activates salivation to promote a soft mouth and bit acceptance. It's angled to lie comfortably in the horse's mouth, promoting good communication between rider and horse. Long-wearing stainless steel rings slide easily through the bit holes for frictionless rein aids. 16mm sweet copper mouth. 65mm stainless steel rings.