On / Off Switch?

I just received my new MinnKota MKA-39 Fisherman's Water Temp Sensor.

I really feel this will soot my needs for reading surface temps and temps down to 10'.
My question is. Is this unit always on?:confused: There is nothing in the direction sheet to indicate there is an off switch. I just figure it's like a clock with a battery, it just keeps running till it's out of juice. Anyone know?

that is a nice instrument. I have a pool thermometer on a string. haha

Hey Slick
Some people still fish with a cane pole... to each his own!

Can't tell from the pic but if it has an on button, it probably turns itself off after a period of time.