Driven by a single 18650 battery, Coil Master 521 mini Tab is a handy compact device for vapers. It allows users to use it as a build deck and is able to dry fire their coils down to 0.1 ohm as well. Reverse battery protection and short circuit protection are also built in for safty use.
Coil rebuilding deck
Reverse battery protection
Short circuit protection
Battery out put voltage testing