Vinyl coated steel resists corrosion and cold climate cracking, ideal for replacing rusted or damaged OEM style traysDrain slots prevent fluid accumulation and aligns with mount holes or brackets11" tray is designed for standard Group 24 size batteries, also fits Groups 1, 2, 17, 22, 23, 42, 54, 55, 56, 72, and 7413" tray is designed for standard Group 27 size batteries, also fits Groups 4, 29, 31, 53, 60 and 77Polyethylene tray is light weight and non rusting