Rigid PVC nonmetallic raceway system. Smooth finish. Packaged in easy-to-handle 5' lengths. Running wires through the channel is no problem with the Sure-Snap System. The snap together base and cover make it safe and simple, positive locking feature deters children from opening. Just drill and screw the channel base to the wall in desired location, lay the wires in and affix wire holders. Snap the cover on, no need to fish wires. UL (Underwriter's Laboratories) listed. Wire capacity: (10) No. 14 THHN wires, (7) No. 12 THHN wires, (5) No. 10 THHN wires; or up to 12/2 with ground NM wire. Use (1) accessory kit for every 5' of wire channel.