Not only are these super AWESOME- the customer service is so great & helpful! I ordered the set (4 wheels) for my daughters plasma car but somehow the post office damaged the package and one wheel fell out. I took photos of the package which was clearly damaged, ripped open, and repaired with tape and I emailed it to DT. They responded IMMEDIATELY and sent out the 4th wheel ASAP. I was so happy and relieved. My 9 year old, 6 year old, and 2 1/2 year old ride their Plasma's daily and these new wheels have made their play time a million times better. I even enjoy the plasma car more now than ever. These wheels make a huge difference. Assembly is fairly simple, I was able to pop off the old wheels and snap these in. A screw driver helped me pry open certain areas, which maybe wasn't the best way to do it, but it worked. I highly recommend the product and the seller! (PS the photo I attached to my review shows the Plasma Cars, two of which are newer ones, and the one on the left is from several years ago. I don't think the new wheels were on yet, in this photo. But these are the ride-ons that the wheels are compatible with.)