Set of 2 Chrome Roller String Retainer Trees Guitar Parts A pair of roller style guitar string retainers The rollers on them can lessen the stress on your strings, which allows the guitar to stay in tune longer They also can prevent wear and tear on the strings, which results in longer string life Compatible with electric guitar and bass Base Size (L x W): Approx. 0.43 x 0.23 inch / 11 x 6mm