This thermocouple assembly is a perfect drop-in replacement for the Mr. Heater Big Buddy propane heater. Exchanging the actual thermocouple pilot assembly is easy, the trick is carefully disassembling the heater enclosure to permit access to the thermocouple pilot assembly. I suggest taking photos at each step of disassembly to make re-assembly that much easier. Five minutes to change the thermocouple pilot assembly but about 10-15 to actually open up the heater enclosure to get access to the thermocouple pilot piece. The replacement part arrived promptly but I have since seen better pricing elsewhere. For these reasons I rate it four stars on ease of installation and value for money. Overall, I'd say 4.5 stars. My pilot light now stays lit and everything works like new again.