100% PG 9mg nicotine shot.
These are used to top up any shortfill to the correct volume whilst adding nicotine and thinning the juice slightly.
9MG are used in place of 18mg to give a final nicotine strength of 1.5mg
50ml add 1 x 9mg for 1.5mg
100ml add 2 x 9mg for 1.5mg
150ml add 3 x 9mg for 1.5mg