Well its been 2 weeks now and i been trying 2 diffrent models....The DSE901 & the RN4081 ....Both work very well,but the RN4081 has a small cat so dosnt last nearly as long as the DSE901, so what i did was take the sponge out of the DSE901 & put it into the RN4081 ... Good result it lasted as long..... So now im looking for a supplier for both models with good boxed packaging...So if anyone can supply me please send information to my bebo site ..... Just log goto bebo and type in ecig. My orders would be for around 10 to 15 kits ....Thanks to anyone who can help.