The super compact KandyPens C-Box is a concealer box battery for liquid and oil tanks. Compatible with any 510-threaded tanks with diameters under 9.6mm, the C-Box delivers smooth, flavorful hits from your favorite concentrates. Attach one of the two included magnetic adapters to the cartridge for easy snap-on attachment. Variable voltage lets you customize your clouds with four optimized settings (Blue 3.4V, Green 3.6V, Yellow 3.8V, Red 4.0V). Developed and designed in the USA, the KandyPens C-Box battery keeps your cartridge hidden for discreet sessions.