The Macurco Security Series are reliable, lightweight and aesthetically pleasing gas detectors made to keep you and the people you care about safe from harmful gases in residential and light commercial applications. The Macurco CM-E1, GD-2B, GD-2A and HD-11 are low voltage gas detectors designed for use with Fire and Security Systems. The CM-E1 and GD-2A are UL 2075 Listed for use in residential and commercial applications and are also approved by the California State Fire Marshal.