UPDATE: They have excellent customer service. They respond very quickly. Also, we got another set (from another brand) with a motor, and it works perfectly. I just really love the colors of this one and wished it had a version with a motor. My 6-year-old son and 4-year-old daughter are playing with these. They sit quietly forever. They love it!This toy was a hit for my 6-year-old son. He could follow the directions by himself, and he has also started making his own creations. I like that this is more realistic in the sense that it has like screws, washers, nuts, so that if he has the real thing, he will know how to use them.My main problem with it is that the nuts do not screw in as tight as we’d want it to be. If you play with it too much, it will loosen easily. Also, the string it came with fell apart in less than a week of use.It is generally still an awesome product. I would still buy it again to have more parts to play around with.I bought this for my cousins and they absolutely love it. They are twins and both 10 years old. They opened the box and they had a lot of fun building it. Durability is another factor that I love about this toy. It stays sturdy when it is assembled and that is one thing I look for because sometimes other toys fall apart easier when it is built but NOT THIS ONE! You can't really go wrong with buying this toy, especially for the price! I recommend it if you have kids or want to give it as a birthday gift to one of your siblings!This gift to my grandson was an instant hit. He remarked that it was his favorite gift. Multiple projects to build. With full instructions..however some pictures were hard to understand the steps. Otherwise a great gift.My son was super excited about this gift, but the instructions on how to build is a little complicated for his age. Definitely need two adults to help.Excellent toy!!! with my son, we have been building all the different models together and he seems to enjoy a lot the fact that after we finished assembling it he can actually play and move different parts of the vehicles or construction models.This has been such a fun project for my daughter and husband to complete together. She loves using the tools to create all the different toys! It’s provided several hours of learning, bonding and fun!The STEM building toy was a hit with my 9 year old grandson. This activity happily engaged him for a couple hours. The set is missing one piece, but my grandson went on building a project not requiring this missing piece. I would recommend this building toy.My children love to use them to make cars and build houses.At first, my children were disappointed when they saw the box. They opened the box and started to build. It was a good thing to hear the children talk about their design.We've had two days, and every day they sit together, designing and building together.