I've used other puck light type led's before, but they always fell apart after a few weeks.  These lights are solid, well built and actually have some 'heft' to them. The batteries are already installed (just remove the plastic tab) and that's a huge plus in my book. We'll see how long they last, but we're off to a good start. I've placed one in my under-sink cabinet to shed some light on that scary place. A piece of 2-sided tape and we're in business. Enough light to see what I'm looking for.  The tap on/off is easy and solid.  Only thing I've yet to figure out is how to set the auto-time off. Product description says you can have it turn off after "X" number of seconds, but no clear way how to achieve that. I took off one star for that, but otherwise s'all good.