These are memory locks for fixing the height of stands. There are three types, as detailed below. ■ Maxtone: 2 pieces (top row of photo 1) ■ Pearl: 4 pieces (middle row of photo 1) ■ Probably Yamaha: 2 pieces (bottom row of photo 1) All of them are compatible with 22.2mm diameter pipes. They might work with pipes that are about +-1mm different if you widen or modify them slightly. All of them are in clean condition with no rust.