Basically and small gadget that houses the atomiser, you drip your juice directly onto the coil and wick and vape away, it means you have to top up frequently but the taste is so much nicer, fuller, than vaping through a tank full of juice, IMO.
No leaks. You have control of the ohm, volts, wattage through your Tesla. Drippers (RDA's) are very reasonably priced, (I paid less than a tenner) and very little can ever go wrong because you rebuild them yourself, which is easy enough to do.
If you like tanks to hold juice then pro tanks are very good, usually. I also like the evods and have recently had a go with a davide tank. Pretty good. But, no comparison to my RDA.
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Have you checked the seals and o-rings in your PT?