There are four different buffer units available for the Type 21 ranging from 50mm to 200mm.The Type 21 is a small unit with a lower capacity than other Oleo buffers so would generally be found on smaller cranes.These buffers are also used in steel mills as a stopper for hot slab works using multiple units.
| Metric | |
|---|---|
| Stroke | 50 mm |
| Dynamic Capacity | 10 kJ |
| Maximum End Force | 250 kN |
| Static Start Force | 3 kN |
| Static End Force | 16 kN |