1.CIRCULAR COVER WITH CIRCULAR FRAME 2.AS PER ISO9001 AND EN 124 ... Quick turn around time and shipping.ADVANTAGES 1.Anti-theft: cover and base frame integrate connection, hinge-type opening, sledgehammer hit ... of ductile iron is fourfold that of ordinary cast iron, close to steel materials, suitable for all kinds of road use ... , single unarmed can be open, convenient downhole maintenance! MANHOLE COVER