I used a pair of these wheels for my 1.5Kg combat robot and they worked really well. they've got decent traction, though they'll lose out to Banebots and Pololu tyres, and they can take some serious beating. They're pretty light too which is always a plus, just be prepared for them to weigh in at more than a plastic equivalent. The machining quality was pretty poor on some features, but not critical ones. The threads were decent and the wheel is perfectly round (or at least round enough that I didn't notice any issues) but the finish isn't great and the lightening holes are pretty wonky it must be said. So, a good choice for combat robotics due to their strength and low cost, but not pretty to look at due to poor finish and wonky lightening holes.