Poor quality!
The tank on my Aspire Aspire K Lite stopped working after only two weeks - I couldn't change the coil due to a broken spring (ore something) - when I talked to a guy at another store than the one I bought it, he said that it was a common problem. I bought 2 Vaporesso kits, and their quality is of a whole other league. Stay away from Aspire, and buy something from a propper brand like Vaporesso instead.