This Honeywell XL50A-UPCCBLON controller is a great addition to any HVAC control system. With its excel 50 type programmable design and 24V power supply, it is sure to meet all your control needs. The unit is made in Germany and is compatible with a variety of Honeywell products. The brand name Honeywell speaks for itself when it comes to quality and reliability. This model, XL50A-UPCCBLON, is no exception. Its programmable design allows for endless possibilities when it comes to control options. Whether you're in need of a replacement part or simply upgrading your system, this controller is the perfect choice.