Marina Flexible LED Air Curtain - 53.34 cm, 12 Green LED lamps
1/ No on/off switch, you have to plug in/out the DC power block. Slightly annoying, I've yet to modify it to have a switch.
2/ The idea is to stick in to the BOTTOM of your tank, which you'll have gravel and stones there, so there's no way it's going to stick to the bottom of any tank! I had to make two special brackets to hold it to the side of the tank instead! Not easy. No, you can't turn it through 90 degrees, then the LEDs will dazzle you! They have shades to throw the light backwards, which are fixed, so it has to be the one way up.