MADE IN USA. The Survival Laser Fixed Current Driver is a custom "buck" type switching power supply current regulated diode driver circuit, capable of delivering from 220mA to as much as 1.8A of regulated current at a recommended input voltage of 4.2 to 8.4 volts. The switching regulator IC chip has an efficiency as high as 92%, which means that no driver heat sinking is required for most current outputs. Driver circuit board is 16.8mm in diameter and is designed to fit P/N SL-PBR1 Pill & Brass Ring, which in turn fits the C6, Survival Laser S4 and Survival Laser stainless steel host assemblies. Lead wires are 1-5/8" long 26 AWG silicone insulated for flexibility and durability. Available in 220mA, 445mA, 530mA, 1A, 1.5A, and 1.8A (+/- 5%) current output options. Note: Brass ring not included, must be purchased separately.