ILM Alloy Steel Elbow Knee Guard Pads 4Pcs/2Pcs Kit (2Pcs Kit) Made of Alloy Steel Much Harder and Stronger than ABS or PP Pads Fasten Button Which Keep the Pads on your Elbows and Knees Steady Fixed Nail Makes the Pads Solid and Secure Inside Foam Allows for a Greater Degree of Comfort and Protection for Elbows and Knees Dimension of elbows: approx. 19x14cm/7.5x5.5". Dimension of knees: approx. 23x16cm/9x6.3".