Uniform (12449/19)

Please could I receive the following information;

1. Do your officers wear white shirts or black wicking shirts whilst on operational duties.
2. In what year do the change from white shirts to black wicking shirts take place.
3. Are male officers still issued with custodian helmets.
4. If not, when did this change take place.
5. If not, what headwear are they issued with instead.