OPEN TO 40MM: : It is a multifunctional double ball head with a bottom clamp and 1/4 inch screw, the clamps open to 40mm. It can attach a monitor or video light at the other end, while clamping the accessories with a diameter less than 40mm, such as DJI stabilizer, stabilizer, video C-stand, etc. Note: The maximum load is 1.5kg.360 Adjustable: : The double ball head of the magic arm can be adjusted 360, and you can freely adjust the position of the monitor by adjusting the knob. Simply tighten the knob to secure equipment at both ends of the double ball head. Arm length: 89.5mm Direct Mount: : Can be mounted directly on a DSLR or camcorder shoe mount and mounted directly on any rod, tube up to 40mm in diameter, and allows for the attachment of a full range of video accessories. Multiple Accessory Mount: : Super Clamp Mount Can also be used as for GoPro mount on a rail or hold a microphone on a boom arm, the number of small cameras, monitors, compact cameras, phones, flashes, handheld gimbals and other devices, such as for GoPro cameras, Nex mirrorless cameras for Sony, RX100MK4 etc. Compact and Lightweight: : Made of aluminum alloy, solid and sturdy, also with a protective dense rubber pad on the clamping area to prevent scratches and the entire arm can be detached. This product consists of our Crab Clamps 735 and our Magic Arm 2163.