You get 3 cartridge of insulin out of one vial of insulin for the accu-check 1 full cartridge carries 315 units of insulin...
I use on adverage 20 units of insulin a day, so one cartridge lasts roughly 15 days, so 2 vials lasts me 3 months :roll:
I find that if it starts getting very warm I have to 1/2 fill my cartridges otherwise it can go off a bit near the end of the cartridge...
I actually never use the plugs when I haven't got my tubing attached even when bathing, as the canular has a self-sealing seal same as the vials, so nothing is going to enter... mind you if I went swimming in the sea or public baths I think I would use one then, just for reasurance purposes..
I've found that I've not needed anything to aid removing the dressing, and not found residue to be a problem... Never bothered with applying anything to aid healing either any marks from the canular fades very quickly so only ever have a couple of marks at any one time..