1. The tripod mount ring is made of high quality Aluminum, precisely machined by world-class high-end CNC turning center, hollow-out weight reduction design, and solid; polished and anodized , appearance and exquisite workmanship is much similar products made by mold; 2. The tripod collar is customized according to the lens. Cannot be rotated. Accurate shape design, avoided the adjustment knob and the switch of the lens, will not affect the original functions of the lens; strong and sturdy; 3. Multiple rubber sheets are embedded on the contact of the lens collar and the lens to protect the lens from wear, the rubber is about 0.5mm higher than the contact ; 4. The bottom of the lens support is added Arca fit quick release plate, the length of the plate is about 46 mm. 1/4 and 3/8 screw holes. 5. This lens holder bottom Quick Release Plate is 39mm,for compatible with for / / / / MARKINS / PHOTOCLAM / / / / MARSACE / ball of Arca 39mm fit, suitable for IS-JZ30 / IS-JZ50 / IS-JZ64 / IS-QJ58 / IS-QJ64- / IS-JZ60BK / IS-JZ70MFT / IS-JZ80BK. Applicable to: for -E 17mm f/4L Tilt-Shift Lens for -E 24mm f/3.5L II Tilt-Shift Lens Material:aluminum colour:black Package Contents: 1 * Tripod Mount Ring IS--E1724II Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.