Ultradyne UD Chassis Bridge Sniper Grey. The Gen 2 model offers a three-piece design where the top can be removed to remove the barrel without removing the M-Lok hardware and side pieces. This provides a strong interface that positions the Picatinny rail at the right height for mounting most night vision devices. The UD Bridge is an essential component for shooters who use night vision and want to securely attach it to their UD Chassis. Specifications for Ultradyne UD Chassis Bridge: Manufacturer: Ultradyne Fabric/Material: 6061-T6 Aluminum Length: 3.9 in Width: 1.9 in Diameter: 1.25 in Height: 2.1 in Weight: 5.4 oz Features of Ultradyne UD Chassis Bridge Aligns with receiver Picatinny MLOK hardware included Removeable top for barrel removal Package Contents: Ultradyne UD Chassis Bridge Installation Hardware Included Ultradyne UD20180-SG: UD Chassis Bridge Sniper Grey