Constructed of heavyweight vinyl truck tarp material for increased durability. Orange bag measures 12 x 20 inches and is designed to hold 18 inch long sections of 4x4 cribbing. Black bag measure 12 x 20 inches and is designed to hold 18 inch long wedges and shims. Adjustable cinch strap secures the top of bag. Removable shoulder carry strap. Most engines carry a compliment of two orange cribbing bags and one black wedge bag.