Feature SCCON-SW2 a Built Tough with Rugged Aluminum Alloy Material, Stay Solid and Resist Bending a Easy Fit with Half-Open Design, Can Fit Diameter 33.5-35mm of Side Focus Knob a 5mm Width Wheel Hinge for DIY Sticker Markings to Track Your Adjustments Easily Specification Outer Diameter: 88.2 mm / 3.47 in Inside Diameter: 36 mm / 1.42 in Weight: 75.5 g / 2.66 oz Material Aluminum Alloy Items in the Package: One Pair of Spare Plastic Sealing Rings, T15 Torx Wrench, Screwdriver, etc. Easy of Use: Loosen the screw, slide the side wheel onto the side focus knob and tighten the screw. Size