The Trojan 602856 is the correct replacement UV lamp for the following filter systems:
The Trojan 602856 - PRO-30 Replacement UV Bulb is compatible for use with the Trojan UVMAX Model J, J Plus, K, K Plus, and PRO50 ultraviolet water filter systems. This Trojan UV bulb includes 2 O-rings and has a life of 18,000 hours. The Trojan UV lamp is environmentally friendly and highly efficient. This Trojan UV light replacement helps your UVMAX system reduce Cryptosporidium and Giardia, bacteria, and viruses in your water.
Trojan 602856 - PRO-30 Replacement UV Bulb specifications: