Fresh wort kits are often very difficult to open as they are sealed when they are hot and the plastic is softer. These spanners make it easy and are essential if you often brew with FWK's. They also have an insert for removing plugs in the tap outlet of HDPE cubes and fermenters and a hole to help tighten and loosen fermenter taps.
 
These are also suitable for use with the new Fermentasaurus dump valve assemblies.
 
58mm cap diameter, red version shown in photo. Current stock is supplied in Blue colour.