High end perforated Precast Drain cover slab with M-40 Grade concrete and laminated finished making form FRP formwork and well reinforcement. Size Available. We can customized any sizes and design. Standerd Size. 1) 1275x1000x75mm 2) 1050x1000x75mm 3) 800x1000x75mm 4) 600x1000x75mm 5)