This is not an essential piece of kit, though makes life easier and is a much cleaner way of delivering grout to the back of the prepared slot in the brick. We  manufacture this in stainless steel (unlike  alternatives made with aluminium) The surgical grade thin wall stainless steel 0.3mmm thick  allows for maximum flow rate of grouts and for larger particle materials used in repointing sand. Ideally paired with our StrucSol Grout gun