Lumenok DIY Jug Light.

The Lumenok DIY jug fishing light is made to be easily adapted to a jug fisherman’s preferred floats. The kit includes all of the components to be mounted to the inside of the cap of any translucent plastic bottle or jug. Its design requires only that a small hole be drilled in your bottle cap. When mounted in the jug, as demonstrated,  the light module will remain unlit, as the ball switch is suspended below horizontal as it floats, The rubber tube connector allows for that. When a fish bites, the jug is pulled past horizontal. The ball switch closes the circuit and the light lights.

These are available in red and green and come in packs of 3.