ZZC
| Model | Type | Way of driver | Suitable for Kelly | |
| Square(in) | Hex.(in) | |||
| HDs | Heavy | Square Driver | 3--6 | 3--6 |
| 27-HDp | Pin Driver | 3--6 | 3--6 | |
| 20-HDP | Pin Driver | 3--6 | 3--6 | |
| M | Medium | Square Driver | 2 1/2-51/4 | 3-41/4 |
| 20-MDp | Pin Driver | 21/2-41/4 | 3-41/4 | |
| 17-MDp | Pin Driver | 21/2-41/4 | 3-41/4 | |
| s4 | Light-duty | square Driver | 21/2-41/4 | 3-41/4 |
