Breve is a manufacturer of speed controllers for fans and heaters. Speed controllers can be controlled by a 0-10V DC, 0-20mA signal or by the MODBUS protocol. The HVAC product range also includes single-phase (autotransformer and electronic), three-phase (autotransformer) and DIN rail controllers. In addition, BREVE offers programmable thermostats and voltage setters. Details below.