Tub of Easyjoint (Horwich BL6)
Mushroom coloured jointing compound/grout. Says 12.5k on side. How much it will cover depends on the size of your spaces between flagstones. You wet the area and then brush it in. It's been spare for a long time but never been opened so should still be ok to use if you have a bit of path/patio pointing to do.
This offer has been gifted to someone and is no longer available.