A/C Solutions BMW E30 R134a Safety Pressure Switch (black) (64538390971)The high pressure cut off switch is used to disengage the A C compressor when the system reaches maximum pressure. Unlike your original switch, this is specifically designed for R134a as the high pressure side operates at a higher PSI than that of R12. Whats included? R134a safety high low pressure cut off switch Fitment notes: This switch is compatible with the late model E30 filter drier. For use with the following models: BMW E30 (all) Cross