i was tired of the wasp nano bf pin. no problem with it but it sits flush with the base so very little juice remains in the juice well when you let go of the bottle so i tried to see if i have something thatg will fit and stumbled upon one of these. it fits very very well and now the pin sits a bit higher like 1,5mm so now some juice remains for a few extra drags. overall a very good choice and it doesent interfere with the coil at all