Function: 1. IS-SM1560C metal lens tripod bracket ring with quick release plate is suitable for Sigma 150-600mm f5-6.3DG OS HSM C lens. 2. Using aerospace aluminum, precision CNC machining, hollowed out to reduce weight, grinding and polishing, anodic oxidizing surface, with stainless steel screws. 3. It adopts the original standard, inner diameter about 80.5mm, width about 22.5mm, increases the function of quick mounting plate, plate length about 75mm, with 1/4 inch and 3/8 inch screw holes and non-slip stainless steel screw. 4. The quick release plate uses the AS standard, compatible with the standard RSS/ARCA SWISS/KIRK/WIMBERLEY/MARKINS/SUNWAYFOTO/KANGRINPOCHE/BENRO/SIRUI/MARSACE/ISHOOT ball head, applies for IS-JZ30/IS-JZ50/IS-JZ64M/ IS-QJ-IS-64 5. Professional production, stable characteristics and high reliability. Specification: Item Type: Lens Tripod Ring Model: IS-SM1560C Material: Aluminum Alloy Color: as shown in the pictures Mounting: for modern Sigma 150-600mm f5-6.3DG OS HSM lens Weight: approx. 245g Inner diameter: approx. 80.5mm/3.17in Width: approx. 22.5mm/0.89in Quick release plate length: approx. 75mm/2.95in List of packages: 1 x Lens Tripod Ring 1 x Internal Hex Key