Crossbar Hidden Countertop Support - 24"L Low-profile plates provide a clean, "floating" look for your kitchen countertop Hot rolled steel with black powder-coated finish for strength and durability - tested up to 500 lbs. Mounts on cabinetry to support extended countertop overhangs for island applications Supports up to a 18 overhang in 2 directions  countertop can extend 6 beyond the support CrossBar support bracket for corners of cabinets  supports should be placed every 16 to 20