The A350A/B Temperature Control Is Housed In A Compact Nema 1 Plastic Enclosure Designed For Standard 35 Mm Din Rail Mounting. The A350A/B Is Not Position Sensitive But Should Be Mounted For Convenient Wiring And Adjustment. Four Key-Slot Mounting Holes On The Back Of The Control Case Are Provided For Surface Mounting. Add-On Modules Must Plug Into The Right Side Of The A350A/B Control. . Made in United States. Manufactured by Johnson Controls.