RD221-MB-B-O-N is a type of Carling Technologies toggle switch. This toggle switch is a two-position, break-before-make, on-off, normally open switch. It is a miniature double-pole version of the RD2 series, which measures 10.2mm x 11.13mm and is available in four colors: red, black, orange and white. The switch’s body is constructed with plastic material, its electrical components are rated for 12V AC/DC current and the contacts are silver plated. This type of switch is commonly used in automotive, audio/visual and communication systems.