Unfortunately the bottom try and done were smashed when I received packageBoth of these kits arrived a little banged up and one of the light bulbs is notably a tad dimmer than the other. The product packaging displays these units as being stackable, but I don't see how this would be structurally feasible. The plastic dome is of a high enough density to resist most bumps and dings, but not quite enough to support a 2nd unit stacked on top of it with watered soil. And that's not too mention that the top unit of the stack would actually be resting its weight on the flat surface of the light fixture, which gets relatively warm/hot to the touch. This would also cause the light reflector to be pressed down uncomfortably against its respective dome top.The daisy chain extension cord is about 1"–2" too short to use when both units and their respective lights are sitting parallel with each other, making them almost only chainable when set in an end-to-end orientation. The extension cord is long enough to use with lights that are "bridged" perpendicularly across 2 parallel domes as pictured on Amazon, but I feel this produces poorer light distribution than having each singularly run down the center of its own default dome.Also, as a fault in the design of most seedling dome trays, the moisture droplets have enough opportunity to bead their way out along the outer bottom edges of the dome. All the manufacturer would need to do is have a recessed edge where the molded dome plastic barely dips down passed the top inner lip of the tray before coming back up to resume over that tray lip. To remedy this myself I took long pieces of white duck tape and folded the adhesive side length-wise back over itself just enough to leave 1/2" of adhesive exposed along the length. I affixed this adhesive along the bottom inside rim of the dome so that it recessed down inside passed the tray top when resting the dome onto its tray. All moisture beads now run back into the tray, not outside of the system.Seedlings are growing well. But not sure whether the price justifies the product... but just barely.I already owned 3, bought 3 more. they stack very compactly when not in use/off season storage. (keep the light's box to store the light and reflector safely in.) The lights are Very Bright. and though they get a little warm, they don't get hot. and they sit securely in the groove on top of the nanodome. I have three other 7" domes to cover seedling flats, but I like these the best. They are super clear, and the vents are nice.Update: I bought the first three from outside Amazon loved them, so bought more here on Amazon. I was shipped damaged items (the outer boxes were fine but the inner boxes and products were damaged and had obviously been returned at least once. They were also not as originally packaged. The product itself is a very good product, but the seller needs to be scrutinized closely for reliability and care in shipping something made of thin plastic-- should be shipped like glass. carefully. and NOT ship out damaged goods. I returned the damaged items (2 of three ordered) and reordered 2 more from my original vendor who packed originally packaged items carefully for shipment-- Ali's organic.Update 2: Amazon fulfillment center was responsible for shipping the damaged boxes/products. the following was from the company that I ordered the minigreenhouses from--""Sorry to hear that Amazon shipped you 2 damaged mini greenhouses when we put them on sale last week, but I see they refunded you already from our account. They are responsible for shipping and for ensuring that any items we sent to them for fulfillment arrived in good shape and are not sent on damaged to our Customers. If they arrive damaged at the Amazon fulfillment Center, they are supposed to be set aside as unfulfillable and make a UPS insurance claim, which they apparently didn't do.""This is a very good product. I'll rate it as four stars since it's only just arrived. I'll come back to update the rating as time goes by.The plastic is indeed light-weight but that's not a bad thing. It seems sturdy enough to go through normal daily use in a home, I'm not a professional gardener so I can't say if this is strong enough for mass growing of items. Certainly it's strong enough to hold the light that comes with the kit and it keeps the temps steady inside.Speaking of lights, this had an unexpected benefit for the home. I'd placed the unit in an relatively unused corner with a timer to turn the light on and off at various times in the day. I'm very happy to say that the dark little corner is well-lit now with happy little pseudo-sunshine :)I rounded the corner the other day and was pleasantly surprised at how much cheerier the room had become. I'm tempted to get another kit to place in another corner, ha. One can never have too much greenery in the home I guess.The light has produced good results. You are really buying the light as the tray is a common tray that you get for free when you buy for the garden center. The lid is fine. I would be really pleased if the price was about 40% less. I am going a different/cheaper direction in the future.I love to start my seeds in the late winter to get my plants a head start! In the past I’ve set up a huge set of lights that takes up the entire table, so I decided to try these out.The kits works really well! But I cannot give it 4 stars for a few reasons:1) the full shop light greenhouse I set up is leaps and bounds superior to this kit. The plants grown in this kit were just not as healthy and happy.2) the lights only really support what was in the very middle of the dome. The plants on the edge just didn’t receive the light I had hoped.I loved having just one that was simple to set up and took very little space, but if I want to grow more than a few things I will definitely use my bigger rig rather than buying another one of these.the Dome was crake but that ok I bought a second knew some damage was coming