Cold Shoe Adapter with 3/8" to 1/4" thread 814
The Cold Shoe Adapter 3/8" to 1/4" is part of the CoolArm11, and may be used to mount an accessory with 1/4" socket to the hot shoe of a camera.
The thread is 3/8" to 1/4": the thread top part is 1/4" , bottom part is 3/8".