An easily selectable range of 11 preferred value carbon resistors from 100W to 10W. Values (in ohms) are: 100R, 330R, 1k, 3.3k, 10k, 33k, 100k, 330k, 1M, 3.3M, 10M. Each range is rated at 0.5W continuous, 1W maximum. Housed in a robust ABS plastic case 75x100x40mm with rotary selector switch having an OFF position. Connection is made via a pair of 4mm sockets.