The Pin Drive Roller Kelly Bushing is made up of top cap bottom seat shaft roller floating ring transmission pins fixed bolts oil cup etc
1. Pulling out or feeding off string can be done while rotating
2. Because of its integral construction it can not fly out and hurts you
3. The bushing is easily installed into the master bushing maintaining good alignment
4. The contact between kelly and roller is rolling contact so friction is lower and weight on bit is accurate
