Stegmeier MS008 9/16″ x 5-9/16″ x 10 Slip-N-Join Couplers 6 Per Carton 12' Lengths is a reusable forming material that is designed to provide excellent performance on radius forming projects. Slip-N-Join Lumber is light weight and easy to bend into a consistent radius. Slip-N-Join Lumber will not warp or swell from water absorption. Sections can be connected with included couplers.