Ultra lightweight. Use gorilla glue if you want the edge protectors to stay on. Apply generously and wipe the drip away. They work very well. I glued foam pads to them and took off the straps. You could use the straps and kneepads though. I just don't know anyone in the business who would. Metal boards tend to pull a bit under the knees. Not much of a problem, but if you were looking for something that won't go with fiberglass. I like these better because of the flared ends. Fiberglass ones very flat and concrete cakes up over the edges. Not big problem. However, these things slide like butter on ice. Watch yourself getting on. Kinda dangerous if you're not expecting it.