DC Rotary Engine for Fast Dust Removal, Charge-Enhancing Nano Coating, Powered by 1 AAA Battery. The Arctic Butterfly SL 707 from Visible Dust is a tool for cleaning the sensor of your small digital SLR or mirrorless camera. Its compact size allows it to fit easily into your gear bag. The patented design includes a DC rotary engine that generates optimal centrifugal force which enables fast dust rejection--without the use of canned air--while increasing the charge of the fibers. The Arctic Butterfly uses extremely thin Super Charged Fibers (SCF) that feature a nano coating for charge enhancement enabling maximum dust removal. A metal ferrule attaches the fibers of the brush to the main body of the tool via a non-conductive joint. The SL 707 can even be used safely on sensors coated with Indium Tin Oxide (ITO) or on those in DSLRs having built-in sensor cleaning systems. It requires 1 AAA battery (not included).