A multi cache starting at the bridge over the railway on St John's Hill Road. There is parking nearby in Holly Hill Road.
You first need to find the values for A-D
At the above coordinates there is an engineers line reference sign starting BML1. The bottom line is ABm CDch.
To find the cache use the following calculation:
N51 18.(D*A)(A*2)(C+1)
W0 34.(C+D)BC
You are looking for a camo'd bullet micro.