Enforcer (also known informally as "the big red key" ) is the term given to a specially designed manual battering ram currently used by British Police forces to aid in gaining entry to premises.
The Enforcer is of a steel tubular construction with a steel pad at the impact end so that it can absorb the impact, and a handle at the opposite end angled so that the user can swing accurately without actually applying his own pressure more than necessary. Further, there is a handle in the middle of the tube aiding the user in handling. The Enforcer can apply more than three tonnes of impact force to door locks, whilst it is 58 cm long and weighs 16 kg.
In London the Metropolitan Police Services' Armed Response Vehicles and most station vans carry them. Within most forces an officer can only use such a tool once they have attended a course receiving training in the safe handling and operational use. Also, most forces insist that the user wears gloves to minimise the shock created when a door is struck with the ram.
Enforcer Training Manual (PDF)