Kikkerland Solar Powered Rainbow Maker – Prism Suncatcher, Fun Home Window Decor – Unique Gift for Christmas & Birthdays – Double Crystal

These work as advertised. I have several in my house and have given several as gifts. On very sunny days my house is filled with cheerful sunbeams. I've noticed that in intense heat, sometimes the suction can fail and the device falls down, but it's unusual. The device is affordable, especially on sale, and brings so much joy. It's a pleasure to look at. Grateful for a simple device that can bring joy to life.

Cool little knicknack that gives us and the kids morning rainbows. Cats chase them across the floor as well. Holding up so far

While the product is well made, the suction cup can lose grip causing it to fall off the glass. This causes catastrophic failure. Support it with a safety string or wire.

This joins the radiometer and 4" prism as one of the basic sun toys that everyone should have. It's a fun design with a transparent case, exposed motor, different colored gears, and counter rotating crystals. It looks to be quite well made, and I was pleased to find that its large built-in suction cup does a good job. Up close you hear a little whirring sound (not objectionable) from the motor and high speed gear, but from across the room it runs silently. Its speed doesn't vary with the intensity of the light, it either runs or it doesn't run. Occasionally it will click for a few seconds as the shadow of the sun passes over it.I saw one reviewer who said the single crystal unit worked fine, but the double unit was underpowered and would barely rotate in bright sunlight. I don't find that to be the case at all, mine rotates even when the sun is partial obscured by clouds. As I write, it is late on a winter afternoon in New England with the sun low in the sky at 60 degrees off perpendicular, and my double unit is still running. I experimented and found it would even run when the solar cells were illuminated from the back!Minor negatives --- Compared to the one big bright solar spectrum a 4" prism will throw on the wall, the spectrums from this thing are pretty small and dim, though the compensation is that there are many of them and they sweep around the room. When the sun is at the right angle, you have to expect that some of these 'rainbows' are going to pass over your eye, so you get a little flash now and then. It's more complicated than a prism or radiometer, so it's probably not going to live as long.For those interested technically its solar panel is 4 cm x 2.5 cm = 10^-3 m^2 and looks to be five (1/2 V) cells in series. Since the power of bright sunlight is 1,000 w/m^2, if inexpensive solar cells with efficiency in the 5% to 10% range are used, the output power available to drive the DC motor would be 50 to 100 mw, or 20 to 40 ma @ 2.5V.update --- It's now nine months since I put this on a window using the vacuum sucker and it's never fallen off! Still works fine too.update2 --- Well after two years, it's showing its age. One crystal broke off when it fell and the gears are now sticking. I just ordered a replacement.More technical--- When my new one arrived, I took apart my old one to look at the motor, which still works. (I am a motor control engineer.) The motor is not a DC motor with brushes, which is good as brushes wear out. It is a brushless AC PM (permanent magnet) motor that a finger test shows will spin in either direction (at roughly 200 RPM). The 2.5V from the solar cell is converted to AC by a tiny circuit board mounted above the coil. The board's active component(s) is covered by glop, but it is probably a single IC clocked by an external crystal, which seems like overkill.

Great little device while it's working. I have had one for many years, but came in the other day and found it making a strange noise and not turning. Seems one of the little gears split and stopped it from turning. Currently it costs too much so I can justify replacing it, knowing it will eventually fail because of the plastic gears. The little gears on the shafts are pressed on and that causes a lot of pressure on the gear which will eventually lead to it splitting. Being warmed by the sun probably doesn't help..

Beautiful.!

This Kikkerland Solar Powered Rainbow Maker is absolutely delightful! It's a simple yet captivating addition to any window. The crystal prism beautifully refracts sunlight, casting rainbows throughout your room. The unique design adds a whimsical touch to any space. It's sure to spark curiosity and bring joy to both children and adults. The prism is well-made and durable My wife enjoys this everyday. The only con is that having random flashes of light can be unsettling. It took us about two days to get used to this. Old Eyes.

I purchased this item for my son for Christmas. He immediately put it in our living room window and the crystal didn’t turn. The gears were moving slightly and making a ticking noise so we figured the midwestern winter sunlight wasn’t strong enough. In April we started having consistently sunny days and the crystal still didn’t turn even though the sun was pouring through the window. I thought maybe we just needed to wash the windows. Did that. Still not turning. So I searched product reviews to see if other people were having this problem and learned that the weird ticking noise and lack of movement was pretty common. I tried twisting the vertical silver piece where the crystal attaches to see if it was stuck. I was able to twist it, and the gears engaged, but it seemed like it took way more force to twist it than it should. I used a very small screwdriver and loosened the two bottom screws closest to the crystal to see if creating some space in the casing would allow the gear mechanism to turn properly. It worked! It’s a neat prism, and solar powered anything is fun, especially when you can see the gear box work. I don’t love that I spent close to $40 on it and still had to troubleshoot though.