TSG 3-Piece Junior Pad Pack

Our son, who is into various rollersports, is on the skinny side. Most 'youth' products are either mismatched sizes (elbows too big, knees too small, etc.) or are either very inferior products that wouldn't provide protection if you bumped your not-so-funny bone. These are definitely a higher quality product with the plastic caps being large enough to protect the intended areas.
With is mom on a roller derby league, she knows appropriate protective gear. These provide it.
The horseshoe gaskets would also be a good idea to avoid pinch points.