The lights appear to be outdoor lights that have been repurposed for underwater use. I am sure they will give long lasting service as landscape lights, but the upper seals on the lights do not appear to be sufficient for underwater use. They are sealed by just a thin, silicone O-ring, and the cap is a snap-lock cap as opposed to a screw top. A snap-lock cap doesn't provide sufficient, uniform, force to maintain the seal. A screw top would give better sealing power. Even better would be a permanently sealed light with colored lenses that go OVER the light's lens, as opposed to the colored filters actually being the lens, as they are in this case. I resealed my lenses with silicone sealer, as I did not trust the seals after reading other buyer's posts. They did not leak after being submerged for 48 hours.
The bottoms appear to be well sealed, but, I would caution users not to be rough in their handling of the lights, as the lights are fairly heavy, and I suspect that rough handling, or leaving them dangling could break the seals on the wires. Also, any nick in the insulation of the wires, could potentially cause a leak.
The transformer got warm while in use, and I suspect that the transformer may be a bit underpowered for 6 lights. It appears that the company has been adding more and more lights, and they may not have upgraded the transformers as they added more lights to the original set. I know the lights came in a box for a three light set, with a "6" sticker placed over the "3" on the box. Time will tell on that. The transformer is also a bit big for use with covered, outdoor outlets, and you may have to use an extension cord or some other method to plug them in.
There was also a lack of uniformity in the way the light's position could be adjusted. Some clicked nicely into each position, and some just barely clicked.
On the plus side, the lights are bright, but not too bright, giving a pleasant accent light underwater. However, if you like your pond lights very bright, these may not be the ones for you. I also agree with other posters that the red filter makes the light look pink.
The lights are sufficiently heavy to place easily on the bottom of the pond, and the cord length from the plug to the first light was long enough to reach my power source. The price per light was also a selling point for me, as some pond lights are priced ridiculously high.
I like the two pronged plug for plugging into the transformer, and I notice that splitters are available, which should allow for the use of multiple sets, if you have a large enough transformer.

works well but hate the white LED lights. However, you can use the color lenses that came with to change. Miss the warm white lights... hate the LED cold white colors...

These work great, I did do the silicone trick mentioned in the reviews. They were also half price compared to the ones in my local hom maintenance store.

Easy to install. Heavy enough to stay at bottom of pond, not like others that don't sink. I noticed after a month that the lights showed water trapped inside, between the color cover and the light, regardless of the silicon O ring. The other day, one of them started to flash intermittently. Today during the day when are off, I decided to take it out of water to check it. I could see water inside. I opened the lid and the clear color cover to let the water out. The whole light element came apart. One cable already broken by roast. Fortunately it was the last bulb at end of the three so I could leave that end out of the pond to avoid the electricity making contact to the water when power switch on after dark. Amazingly, the other two still turn on under the water. I don't know what to do. Leave them like that for a while, looking tacky...? I don't think the company that manufacture them would do anything about it. If they do I would at least give them a higher review. So sad. They were so beautiful. I had another set years ago that lasted much longer, about three years. This one already not much after only one month! :-(

Good price. Will also connect to 12Volt lighting transformer. I use in a fountain about 8 inches under water. This is my 3rd set. Expect 1-2 years life - They will leak. This time sealing lens with silicone. Will see...