Crafted from aluminum, CNC machined with high precision, featuring a hollow design for weight reduction. Polished and anodized surface with stainless steel screws. Positioning is achieved using the switch and bayonet; it cannot be rotated. All corners are rounded. The interior is covered with a plastic film to prevent wear. Inner diameter is approximately 82mm, width is approximately 18mm. The base includes a quick-release plate with a length of approximately 65mm. It features 1/4" and 3/8" screw holes and stainless steel anti-slip screws. The base has a standard Arca-Swiss dovetail, compatible with Arca Swiss, RRS, Kirk, Wimberley, Markins, and other AS-standard compatible devices. Applicable to: 100-400mm F5-6.3 OS (E-mount) 105mm F1.4 HSM Art (EF/FX/FE/L-mount) Name: Tripod Mount Ring Color: Black Material: Aluminum Package Contents: 1 * Tripod Mount Ring IS-SM105ART (Only the above package content is included; other products are not.) Note: Light and different displays may cause the color of the item in the picture to differ slightly from the real thing. The allowable measurement error is +/- 1-3 cm.