Clearsonic Ax2412X3 72-Inch Wide X 12-Inch High 3-Section Csp Height Extenders With H-ChannelAX2412 Height Extenders add 12 inches of height to standard CSP systems. H channel and hinge are included. The AX2412x3 is normally used as an add on to increase the width of an existing AX2412 system by 72 inches or to increase the height of an A2466x3 or A2448x3. When its time to break down, CSP systems with AX height extenders installed correctly will still fold accordion style for easy storage.