The Zacuto Zred Zwivel is an addition to the already popular Zred mount. The Zacuto Zred Zwivel gives you more adjustability and movement for your RED EVF. The mount slides onto the top 19mm or 15mm rod on your RED ONE camera. The Zred Zwivel mounts one of two ways. If your top rod is 15mm you will get the Z-Mount., if it is 19mm then you will need the Zandy. This Zred Zwivel has the ability to slide the EVF forward and backward, up and down as well as a complete 360 degree swivel, left and right, up and down.