This is the Duratrax 20A Individual Sub-C Battery Discharger. 

FEATURES: Discharges up to 6 individual sub-C NiCd or NiMH cells at up to 20A Conditions individual cells for racing applications Status lights indicate each cell condition Unique lever-lock handles and spring-loaded contacts make cell insertion and removal quick and easy Four gold plated contacts per cell provide optimum durability Built in cooling fan can be powered by load cells or external DC Power Supply, fan input is protected from reverse polarity One year limited warranty (US and Canada only)

INCLUDES: One Duratrax 20A Battery Discharger

REQUIRES: Load cells or 7.2V or 12V DC input for fan operation

SPECS: Battery Types: NiCd or NiMH Cell Count: 1-6 single sub-C cells Discharge Current: 20A Discharge cut off voltage:0.85V/cell approximately***SEE COMMENTS*** Fan Input Power: Load cells or optional 7.2V or 12V DC input Case Size: 5.25" x 4.25" x 6" (133mm x 108mm x 152mm) Weight: 1.2lb (34g)

COMMENTS: Do not leave the cells on the unit for extended period of time as this will cause the unit to discharge the cells down to 0V which may permanently damage the cells. This is used for single Sub C size cells and not intended for use with assembled Sub C size battery packs.