Clearly fluctuating quality. Of the 5 heads I've used 4. Two have held for 2 days of 5 days and a good 12 days. Just installed the 5th head. I have used the heads with an ego-cc. I was on the purchase of the ego-cc clear that the heads are much more expensive than other systems, but I hoped for good quality and was disappointed. The already installed head in the ego-cc has eg. Approx kept 25 days of the enclosed replacement head 4 days ago. Of course, there are wearing parts, but as a quality is unacceptable. I am going to contact my seller, Amazon and Joyetech. I expect a reaction with reference to "wear parts" or only with Joyetech-Liquid to use or to 10ml Liquid throughput must be replaced. Too Bad :( Update 11/04/14: 2 star rating changed to 3 stars because obliging solution proposed by the seller - thank you :). In this sense, I hope to come across a bad batch.
