12" eTape Liquid Level Sensor + extras _ARD_SHIELD_SERIAL Pickup a copy of Make:

Pickup a copy of Make: Bluetooth LE Projects for Arduino

and there is a caret that indicates where we suggest you make the cut

it turns on a ring of 12 IR LEDs that illuminate the nearby area for night-vision shots

The input of these adapters is 1/2" NPT aka National Pipe Thread (tapered) and the output is 1/2" BSPP aka British Standard Parallel Pipe (non-tapered)

12" eTape Liquid Level Sensor + extras _ARD_SHIELD_SERIAL Pickup a copy of Make:The eTape Liquid Level Sensor is a solid state sensor with a resistive output that varies with the level of the fluid. It does away with clunky mechanical floats, and easily interfaces with electronic control systems. The eTape sensor's envelope is compressed by the hydrostatic pressure of the fluid in which it is immersed. This results in a change in resistance that corresponds to the distance from the top of the sensor to the surface of the fluid.