Automation Components MS-RH/KA/P/R - The MS Series remote accessories are designed to be used with the ACI Duct Smoke Detectors to provide audible and visual indication as well as remote test/reset functions. These devices are constructed of attractiv yet durable brushed stainless steel and mount on a standard single or double gang electrical backbox. Early detection of smoke and products of combustion present in air moving through HVAC ducts in Commercia Industria and Residential applications.