Vectronics DL-650M dummy loads are dry air-cooled resistive dummy loads that use a tuned hyperbolic cone, which is optimized over their frequency range. This feature allows for usable power measurement up to 1,000 MHz. DL-605M loads are capable of dissipating up to 1,500 watts average from DC to 650 MHz. A reasonable cool-down period is needed to keep the resistor from becoming permanently damaged (typically 10-20 times the load usage). Vectronics DL-650M dummy loads are ideal for terminating a hybrid four-square antenna controller, off-air transmitter testing, or for universal use in the ham shack or repair bench. They feature an SO-239 (UHF female) connector.