This extra-strong. 7"-diameter, 21.75"-long gooseneck arm is ideal for accurately positioning a small lighting unit, portable flash, gobo, reflector card, or microphone, & securely holding it in place. The arm’s unique self-locking design doesn’t require having to lock any knobs. Its 5/8" brass hex stud, with 3/8" female thread, at one end mounts directly to a Calumet Studio Clamp or Clip Clamp, while a 5/8" brass round stud with 1/4-20 male thread at the other end provides a variety of mounting options. Weight: 1.45 lbs. (0.7kg) Max Load: 2 lbs. (0.9kg)