PLEASE be careful when you buy cheap and nasty electronic components from eBay... This is a public service announcement.
Check the photos below and tell me what's wrong:
Yes, that's right, the legs are different on both items (the Anode and Cathode are REVERSED)... they came from the same packet and I, prior to using macro on my camera, thought they were a lot more similar than they actually are. Either way, you have been warned.
This all came about whilst wiring up these sensors and receiving zero readings.... bastards....