Tripp Lite's SmartRack SRBOLTDOWN provides extreme stabilization and security for cabinets and racks. The bolt-down kit enables SmartRack to be secured to a concrete floor. SRBOLTDOWN includes four concrete inserts, four bolts and four fender washers.Technical Notes:We recommend using a 1/2" concrete drill. Hole must be 4.5" to 4.75" deep. Mark the hole, drill the hole, then tap the anchor into the hole. Thread the bolt into the anchor a few threads only. Tap the bolt with a hammer (with anchor attached) until it bottoms out in the hole, then tighten the bolt.