HOR was a siren manufacturer. Founded by Harry O. Ricci(hence the name HOR). Among other things, they produced the HOR Super Sirex and the Siro-Drone. Their headquarters were located in Stapleton, Staten Island, New York. But a few of the company's sirens were also manufactered in Phoenix, Arizona
A photograph exists of the specifications tag of a Siro-Drone, but the specs themselves have been worn away with time.
HOR's Super Sirex model was their most popular. According to ARS user BadgerSiren, one model has been in use since 1953. Two versions of the Super Sirex appear to have been produced: a two-horned version and a single-horned version. Only one model of the latter has been reported (in Hamilton, Ohio). One fact that is surprising is that all dual-headed(single-headed) Super-Sirex's were all built to rotate.(As stated in a forum about the HOR Story in Airraidsirens.com)
HOR also produced two different models of omnidirectional sirens