The Pearl CHC100: Curved design. Continuous angle adjustment with GyroLock. Diameter: 12,3 mm. Reversible cymbal cup. 3/8" inch receiver (L-Rod style). The Pearl CHC100 Boomerang Cymbal Arm is a curved cymbal holder with a 3/8" inch mount. You can mount the cymbal holder in curved design for example on any conventional L-Rod or cymbal gallows. Thanks to the infinitely variable angle adjustment with GyroLock, flexible adjustment possibilities are available.