This gun is for use with 600ml foil pack adhesives.
It is a high quality gun similar to a 'skeleton' gun but designed to use foil wrapped sausages of glue.
When using this gun make sure you do not get glue on the threads near the nozzle as you will need a pipe wrench to unscrew it if you do...
You may find you need to cut the nozzle opening to c. 8mm and warm the glue in a tub of warm water on cold days to aid the dispensing of less viscous glues in order to save your arm muscles.