There is no functional or technical difference between the two

By utilizing high-grade elastomers and stainless steel components

providing sufficient volt-ampere capacity to manage the inductive loads of contactors

Designed for 120Vac 60Hz systems

applications above this requires specific high-altitude orifice sizing

Vulcain IAQPT-SM-A Monitor Freon There is no functional orThe Vulcain IAQPT SM A is a high precision, wall mounted CO2 gas monitor engineered for demand control ventilation (DCV) and indoor air quality management. As a direct replacement for legacy models including the 90DM4SM C, IAQ SM A, and M 512041, this unit utilizes advanced non dispersive infrared (NDIR) dual beam technology to compensate for sensor drift and ensure long term signal stability. Designed for seamless integration into building management