What is the difference between the 3B1B and the older 3B1A

a durable ball and shaft assembly

Key Benefits Direct Compatibility: Engineered as a drop-in replacement for the discontinued Danfoss 042N4221

this plug-in transformer eliminates the need for complex hardwiring

Easy field adjustment via the screwdriver slot ensures the 2

Johnson Controls T-4002-301 Conversion Kit R-410A What is the difference betweenThe Johnson Controls T 4002 301 Conversion Kit is a professional grade solution designed for upgrading or replacing legacy pneumatic thermostats in commercial HVAC systems. This direct acting kit features a 55 85F dial range, providing precise setpoint control for single temperature applications. Engineered for seamless integration into existing pneumatic control loops, the assembly simplifies the transition from older dual tube or single tube