i heard nanovapor sucks ass. like in the ads, it shows the infrared pic. and the dudes head is hot. well thats all it really does bro. dont know anything about shotgun. but EVERYONE on here, well just about everyone, swears by amp02. i think you have to order online though. theres a link somewhere on here. ive takin NOxplode and liked it. people on here say amp02 kills that stuff. i think ill be gettin my amp02 real soon bro. hope this helps. sorry not much info on the pumps though.