Characteristics: This key is made of qualified stainless steel, solid and strong, after grinding and polishing, the surface is smooth without burrs. The maximum bore is 110mm, with a double head and a flat end which is convenient to use. Three rows of holes allow you to insert the tool deep into the lens barrel and fix it with four round head screws. Comes with 2 hex bolts and a hex wrench, you can use it to replace the two inside hex bolts, use them to tighten the wrench opening tool. Arched design, anti-skid, and lock the screw hole more tightly, not easy to damage the lens. A great accessory for your DSLR camera lens. Technical data : material: stainless steel Colour: silver Suitable for 5-140mm / 0.2-5.5 inch lens Size: Approx. 15.5 x 12.5 cm / 6.1 x 4.9 inch Minimum opening width: Approx. 10mm / 0.4 inch Maximum opening width: Approx. 110mm / 4.3 inch Weight: Approx. 154g Packing list: 2 x hexagonal bolts 1 x hex key 1 x Arc Key Opening Tool note : Be careful not to damage the camera. Please be aware: