The 11mm to 20mm aluminum alloy mini adapter mount is designed to easily convert a 11mm rail into a 20mm rail. to improve the versatility of your optimized accessory compatibility. Each box contains 2 pieces of the adapter, making it a convenient and cost-effective solution for rail conversion. Made of high quality aluminum alloy, provides stable and durable support for attaching accessories such as telescope. Compact and lightweight, convenient to carry, Weight: 0.07495716908 pounds, Manufacturer: Rtxbvg