1. Despite the size - much larger and heavier than those TeckNet LED Nightlux LED Night Lights with motion detector and brightness sensor - enough one of these LED step lights not to illuminate a once-turn staircase safely. You need at least two of them, better even three, and then unfortunately it is no longer the price-performance ratio.
2. It can be due to the back wall design does not attach with double-sided tape, but only with screws and dowels.
3. It is not very difficult - with inserted NiMH batteries (3 x C batteries are not included) weighs around 280 grams it - but on top of that affects pretty clunky because of the dimensions.