These pads have options, run a hard plastic cup or not. They fit great under your clothes we tried it. The knee pads come in 3 sizes for the best fit.
The shin guards are very comfortable under your jeans with the plastic in them. They come in 2 sizes.
Elbow pads are not bulky and fit with out sliding around, they come in 2 sizes.
This guy is a fan of the Shadow pads!