4040R is a 4.00x4.00 CM fractional 40 series square extrusion T-slot profile with two side open T-slots, each side with 4.00cm face,the other side is round face. The profile has align-a-grooves to assist in aligning connecting profiles. The 4080 profile is compatible with all 40 series fasteners and accessories. This profile lends itself to machine guards, sound enclosures, work benches, panel mount racks and displays. The T-slots enable access from any direction and are useful for mounting accessories.