Outwater Black Finish 1/2'' Inside Dimension Aluminum U-channel 36'' Length (pack Of 4) Alu847-bk C-channel in the Furniture Moulding department at Lowes.com
Aluminum Channel – 1-1/2″ Leg x 1/2″ OD x 1/4″ ID x 1/8″ Wall - Eagle Aluminum
2″ x 2″ Formed Channel (1/8″ Thick) | Winnick Supply
Amazon.com: Stanley National N316-463 Weldable Steel Channel, 1/2" x 1 1/2" x 36" : Industrial & Scientific
Kindorf C-105-2-1/2 2-1/2 Inch Galv Krom Steel Channel Mount 2-Piece Conduit Pipe Strap | Cooper Electric
2 1/2 in x 18 Gauge 43 mil Structural Steel Track w/ 1 1/4 in Leg at Capitol Building Supply, Inc.
Everbilt 1/2 in. x 1-1/2 in. x 36 in. Plain C-Channel with 1/8 in. Thick 800197 - The Home Depot