Package has only 1 piece (single), not 1 pair. Relieves joint pain for knee surgery, arthritis, ACL, MCL, meniscus tear, tendonitis. Triple elastic pressure belts and adjustable Velcro design for compression and custom tightness. Medium knee pad fits for kids above 10 years old, teen boys and girls, and skinny adults. Please refer to the knee circumference between 12 - 19 inches(30-45cm). Knee length 7.5 in(19cm). Non-slip silicone strips help keep the knee guard in place, comfortable and effective, you can use these for indoor soccer (goalie), suitable for volleyball, basketball, soccer, cycling, gym, ect. The knee brace has open patella design and patella gel pad surrounds the kneecap for shockproof and decompressive. Double-sided metal spring stabilizers(4 springs) fit tightly with your knee joint which bind up the knee from all angles giving lateral and medial support ideal for weak knees and injured ligaments or doing exercise.