Model no: SA-M1333 This coupler clamp with 5/8" stud is the perfect accessory for any studio offering many possibilities to your studio lighting. This coupler clamp features a 16mm(5/8")stud that allows you to attach your lighting to it then clamping them on to your auto pole or cross bar from 42mm to 50mm in diameter. It gas a protective material on the insides of the clamp to avoid any damage to your equipment.This clamp is made up of high quality materials and finished in black. It is the essential accessory to any studio offering great flexibility with your lighting.