Tough and durable, while still letting you move, the Protec Knee/Elbow Skate Street Pad Set is a great deal.
Impact-absorbing foam covers the knees and elbows, and a shield of impact-resistant ABS plastic caps off the pads. Not only is the foam/ABS combo able to safely absorb most low-to-medium speed impacts, the caps let you slide out any falls.
Includes one set of elbow and one set of knee pads.
Protec Helmets and Pads Fit guide here.