Bought a rangefinder, cant find any documentation

Google told me that Virtual Ink made interactive whiteboard systems. Could be they were using a combination of IR and ultrasonics to track a marker. I'd start by applying power to +5 and Gnd and see what comes out the other two wires. Hiss at it to try and trigger the ultrasonic sensor. Shine a remote control at it to see if it reacts to IR input.