The British prismatic fluid compasses are of high quality and therefor  quite expensive. ( Between 200 - 300 euro)  

SIRS Navigation (the successor of WF Stanley) and Pyser-SGI  (the two remaining manufacturers) are located in Kent, near London. SIRS calls their compass the Model G150 Prismatic Marching Compass and Pyser-SGI calls theirs  the  M-73 or M-88 (aluminium version). They’re  identical to each other in terms of design and features, including sight readings down to1/4 degree under ideal conditions. The MK III  successors have five  tritium light sources. These lights last for about 10 to 12 years. Every component of the G 150/  M-73 can still be replaced.

The serial# and the NSN have been removed. Probably  this compass was stolen.

The scale is in Mils  6400/1000.