Bought this set as it seemed the only manufacturer who offered different sizes for kids. One size kids pads are an impossibility as they can't possibly fit a 5yr old and a 10yr old.
Bought the "small" size, as my son is 5yrs old. Knee and wrist pads fit fine, but the elbow pads are still on the larger size, and the velcro straps don't quite go small enough to hold them snug against his elbows. He will of course grow into them in a year or so.
Quality is very good, but noticed that some of the velcro is not entirely stitched to the pads, so time will tell as to how long the velcro stays attached to the pads.
Otherwise, and for the price and the different size options available, a good buy.