how do you tell if you can re fill it or not,
Although I don't know that brand, most of the UK e-cigs of that type have a cap on end of the cartomizer section (the refill) which you can pop off with the right shaped tool. I used paper clips or mini screwdrivers.
E-Lites (UK) had $6 refills (per refill) and could be filled 3-4 times before turning to mush.
A ''proper' Boge cartomizer costs $1.50 and could be refilled 10-20 times.
Most of these companies use cheap cartomizers designed to not last long and cost lots of money.
Be careful with what you
buy.... Your brands seems to charge $15 for 5 refills. They may not refill many times so you
buy more and more and spend too much money in the long run.