Heavy, steel, spanner wrench makes it easy to tighten handguard barrel nuts to the correct torque. Notched end engages the indexing ring on Yankee Hill handguards and others with similar, slotted indexing rings for aligning the accessory rails. Mfg: Yankee Hill Machine Co., Inc. SPECS: Steel, black oxide finish. 8'''' (20.3cm) long, 2'''' (5.1cm) wide, A 1/4'''' (6.4mm) thick.