40-4040-Black is a 40mm x 40mm metric 40 series square T-slot profile with four open T-slots, one on each 40mm face. The profile is smooth, which makes it resistant to dirt and debris buildup while also being easy to clean. The 40-4040-Black profile is compatible with all 40 series fasteners. This profile is the most heavy-duty in the 40-4040 profile family and lends itself to clean room applications, guards, enclosures, or workstations. The four open T-slots enable access from any direction and are useful for mounting accessories.