I bought this racks and I am very happy and I added a few pictures to help people understand how this works but it took me 40 min to assemble the first shelves. But the second shelves was 20 mins The hardest part is deciding what size I wanted the shelves to go. I bought a 3 set for my garage and they are very strong. If they can hold my tools then that was a good buy.I used this as a storage for my small appliances and it is a solid unit. I put it together myself in about 30 mins. It comes with gloves and a mallet. My first shipment was sent to the wrong place but the seller sent me a replacement which was amazing customer service. I’ll definitely be purchasing from them again for my garage.Using this shelf in my garage. It’s sturdy but not heavy. You can separate the shelf but you cannot adjust the height between each one. I can’t fit tires under mine like the picture showsI love these Reibii shelves. I would describe as more medium duty than heavy duty, but plenty sturdy for residential garage storage I'm using for. I have three different Reibii shelfing units, all with the same frame structure. Super easy to assemble.Very easy to assemble, seems pretty sturdy. Perfect for garage organization. Really convenient that you can arrange the shelves how you like or use them as 2 separate piecesPlastic extensions...bad idea.Works great!