1. The tripod mount ring support foot is tailor-made for Canon RF 600mm F11 IS STM and Canon RF 800mm F11 IS STM, can't be used for other lenses?the measuring volume of the replacement foot is about 91mm(L) x 38.5mm(W) x 31mm(H) (without screws), and net weight is about 95g; | 2. The lens collar stand is made based on the lens structure, the screw holes are precisely coordinated, and the anti-skid positioning pin is designed. It is locked by spring screws, with wavy handles; | 3. The tripod collar stand bottom is added 45mm long Arca fit quick release plate feature, can be used with 39mm Arca-swiss fit tripod ball head, panoramic head and clamp directly; more practical than lens collars without QR-Plate. The Lens collar base bottom reserved 1/4" and 3/8" screw holes and stainless-steel anti-slip screw for fixing lens to tripod directly; | 4. This lens collar support base bottom's dovetail groove is 39mm Arca-Swiss standard, compatible with RRS / ARCA-SWISS / PMG / WIMBERLEY / MARKINS / PHOTOCLAM / SUNWAYFOTO / BENRO / SIRUI / MARSACE / ISHOOT ball head of Arca 39mm fit, suitable for iShoot IS-JZ30 / IS-JZ50 / IS-JZ64 / IS-QJ58 / IS-QJ64-FD / IS-JZ60BK / IS-JZ70MFT / IS-JZ80BK; | 5. The tripod mount ring base is made of Aviation Aluminum, precisely machined by world-class high-end CNC turning center, hollow-out weight reduction design, hollowed-out work processed by Multi-Diamond Cutter finely, lightweight and solid, polished and surface anodized finish. The appearance and exquisite workmanship are much better than similar products made by mold.