Geekvape Max100 (Aegis Max 2) Mod can be attached to Geekvape Z sub-ohm tank. It needs a 18650 battery to power it on (not included). Thanks to Geekvape's great design, this device is waterproof, shockproof, and corrosion-resistant. The purpose of this design is to make sure the kit will not break or damage by accidental falls in your daily life in order to protect the quality. The LED indicator is designed to serve only one purpose which is to make users easily read the basic condition of the mod so you can adjust at your own will without any confusion.