Giottos Calibrated Quick Release Ball Head is a versatile ball head for your Giottos tripod of choice. These replacement ballheads are sturdy and efficient, screwing on to your tripod with a 3/8" thread and securely mounting your digital camera. These tripod accessories feature a sturdy foundation that pivots and tilts smoothly, giving your camera or spotting scope a full range of motion. The Giottos Pro Calibrated QR Tripod Ball Head includes a quick release adapter (either the MH657, MH656, or the MH655, depending on the model you choose), complete with a Giottos sliding plate that allows you to swap out the device on your tripod for another with a single motion. The socket ball of this Giottos tripod accessory is hollow and lightweight for improved motion, and the ball head includes a locking knob and a friction-adjusting tension knob, so you can move your optical equipment at exactly the pace you want. For a sturdy, reliable ballhead with a quick release plate, purchase the Giottos Hollow Ballhead with Quick Release Adapter.