| Model | Fully Extended Length | Retracted Length | Thread | Head Size | Head Bore | Weight |
| JM-1 | 1700 | 1070 | 5/8" or M16 | 142 | 55 | 7.2kg |
| JM-1A | 1700 | 1070 | 5/8" or M16 | 142 | 55 | 6.5kg |
| JM-1B | 1700 | 1070 | 5/8" or M16 | 166 | 68 | 6.5kg |
| JM-1S | 1700 | 1070 | 5/8" or M16 | 142 | 68 | 6.6kg |
| JM-2 | 1700 | 1070 | 5/8" or M16 | 142 | 58 | 6.2kg |
| JMZ-2 | 1700 | 1070 | 5/8" or M16 | 142 | 58 | 7kg |
| JM-2B | 1700 | 1070 | 5/8" or M16 | 132 | 60 | 5.7kg |
| JM-3 | 1550 | 920 | 5/8" or M16 | 112 | 38 | 3.3kg |