The Quick release “popper” attaches to the Arriflex 3/8-16 mount that is located on the handles. It allows you to mount and dismount the MDR boxes quickly with the push of a button. The square receiver on the MDR bracket inserts into the Quick release receiver. The MDR box can be mounted in four different positions. Once inserted it is locked into place. Push the red button to release. This is ideal for moving your MDR box from the Steadicam to A or B camera. The QR Popper can also be used for assistant monitor, or other accessories that may need to be removed quickly. Sold as shown, Anodized black with red release button and red mounting knob. The locating pins for the Arriflex mount can be removed if used on other camera’s.