1. Anti-theft: cover and base frame integrate connection, hinge-type opening, sledgehammer hit not break it, completely anti-theft.
2. Load-bearing great: the toughness of ductile iron is fourfold that of ordinary cast iron, close to steel materials, suitable for all kinds of road use!
3. Corrosion resistant: Sewer internal environment complex, filled with various chemical substances, ductile iron does not suffer chemical corrosion, service life more than 30 years.
4. Opens conveniently: light weight, single unarmed can be open, convenient down hole maintenance!
5. Superior safety performance: It often occurred underground explosion accident, fly up covers scarred passers-by , manhole covers integration connections will not depart from the ground.

1.  Electric power pipeline well; post, telecommunication, communication pipeline well;

2.  Street lamp well, fire control well, all kinds of valve wells;

3.  City water, drainage pipeline well; heat supplied, gas well;

4.  As cover board for anti-corrosion project, open ditch; it as well as can be made according to customers requirements.