This product is one of Foster Supply's biggest movers. It is a complete system to replace the old 12" to 18" flat bottom concrete trenches. It comes complete with a styrofoam form, rails and grates plus rebar supports for leveling. Customers simply level the top of the product, pour concrete around it and wait for it to set up. All that is needed to complete the job is to remove the styrofoam forming material and place the grate on top. What is left is a 12" wide continuous sloped trench with a 14" wide grate ready for traffic.