Y99-G400 rack safely stores four cylinders from 4" to 12" diameter. These racks use two 54" long by 1 1-ž2" wide poly straps for each cylinder station to secure cylinders. Edges are protected with steel reinforced vinyl edge guarding to maintain and protect your cylinders and provide extra grip. Built from heavy gauge (.120-inch thick) welded steel with powder paint finish. Units bolt to floor in four places using your fasteners.Y99-600 shares features with the Y99-400 rack with six (Y99-600) or eight (Y99-800) cylinder stations.