Waterstop is used for construction or expansion joints and for internal or external waterproofing in concrete structures according to British Standard 2571, which are subject to continuous or occasional loads from pressurized and non-pressurized water.
AA BS-type waterstops are designed for externally installed construction joints, which are constructed in accordance with the BS 2571.
| Type | a | b | Pins |
| AA BS-200 | 200 | 70 | 4 |
| AA BS-240 | 240 | 80 | 4 |
| AA BS-250 | 250 | 80 | 4 |
| AA BS-300 | 300 | 100 | 6 |
| AA BS-320 | 320 | 100 | 6 |
| AA BS-500 | 500 | 6 |
