Features & Benefits Self-hanging fingers. Self-aligning side rails. Light weight - only 8 lbs.(3.6 kg) for W-beam, 12 lbs.(5.5 kg) for Thrie-Beam. Bottom tab supports rail during installation. Block is considered a "green" product, environmentally safe and recyclable. Molded product eliminates inconsistencies inherent in wood blockouts. NCHRP Report 350 Test Level 3 compliant. Installation & Repair Advantages Self-hanging fingers minimize the need for assistance during installation. Self-aligning side rails help hold block in place and minimize spinning. Narrower width allows easier access to bolts at splices. Once installed, these blocks maintain original size, eliminating the need for tightening guardrail bolts due to shrinkage often found with wood blocks.