Hastur MTL RTA is designed for mouth to lung and stricted lung hit vapers. And it is designed by Brian N(CA,USA). It comes with 5 swappable air flow resisters(1.0mm, 1.6mm, 2.0mm, 2.5mm, 3.5mm). Bigger posts to reduce the size of chamber. New and easy refilling system. Two 510 drip tips(airhole dia.: 3.5mm & 2.0mm). Food grade 304 stainless steel. 3.5ml capacity.