Review on Upgraded Heavy Duty Rear Bicycle Stabilizers Kit with Stronger Version Training Wheels for Boys and Girls - Fits 12, 14, 16, 18, and 20 Inch Bikes by Adam Matthews

It's easy to assemble but I don't think it will fit all 12" wheels because unless I tilt it the rear wheel lifts off the ground. I also have to grind down some of the metal to fit the bike because it won't fit in the grooves and I took photos to show the parts I had to grind down in the rear tire area. Hope this helps the next person trying to buy training wheels for a small kids bike. I would give higher stars if they matched the bike better and I didn't have a sand part of the bike.