10 XL Bolt on ock Climbing Holds, includes Hardware, by Rocky Mountain Climbing Gear. This Product is meant to be used in 3/4 in plywood, Included in the order are 10x Rocky Mountain Climbing Holds Extra Large Climbing Holds. 10 x1.75 inch alloy steel bolts. 10x 3/8th diamater T Nuts. Look at tutorials on our website to see video installation instructions.