The prawns familiar with automotive cranes or crane rotary turntable bearings (the manufacturer. The structure principle, etc.) look generous with your criticism
There are many domestic manufacturers can produce, we also produce.
Do you have a car crane or a tower crane back to the turntable? Crane or small diameter is generally used to dial the tower crane, one or two meters. Manufacturers: SKF, ROLLEX, HIE, INNAR-FAG, and so on. Many structure: single double volleyball, volleyball, cross roller. The specific circumstances, are discussed in detail.
There are many domestic manufacturers can produce, we also produce.
