[SCOBRAC]

Yea it is a metal tube type. It will mount to the radiator tank or wrapped to to a hose. My 150 had it built in. If I had it to do over I might have gone with an aftermarket external unit with a little more control this one comes with a fixed length of metal tubing the sender uses to transmit to the switch, it actually is a hollow tube that uses pressure to activate the the controller. It's pretty rugged but you need to be careful not to kink it or it will not work properly. You can't shorten it either.

The recalibration of the controller was pretty straight forward but it requires a bit of electrical knowlwdge and I'm sure I voided the warranty doing it. I called Flexalite tech and the guy had never heard of anyone doing it. I explained thew nature of the application and he seemed to understand why I wanted to keep the nearly 40 year old side oiler cooler than the 180 degrees the unit can be adjusted down to. But he wasn't sure how to do it, but promised to get back to me. Well after 2 hours of waiting I got tired of waiting and just did it.

The controller doesn't need to be out of the fan assembly but it is far easier to do this if it is. I took my controller out and did this in the kitchen. I heated water in the microwave. Using an IR thermometer I got the temp to 170-172. Looking at the back of the rheostat there is a hole covered with a sticker, remove the sticker and insert a small phillips screwdriver. Turn the screw slowly counter clockwise to lower the operation temp. The unit will click as it turns on. I used an ohm meter to verify continuity. But as it clicks when the switch is on it isn't really critical. recheck the water for desired temperature a few times to make sure it is where you need it to be. Use a bit of electrical tape to weather proof the hole and reassemble.

I never did hear back from Flexalite tech. I called him a few days later and told him what I did, how it was done. He didn't seem amused.