Hi Charles, it can extend, but not in the normal way. It is essentially a fixed brace whose position can be changed by loosening 2 set screws.
Stay safe & have a great day!

As it comes, fixed with two set screws. Once you remove them, you can move it to the desired position, then reinsert the set screws back.

Hi Charles and welcome. Yes, but there are two locking screws that must be loosened to move it to a desired location on the buffer tube and retightened. Cheers and stay safe! ---- https://veriforcetactical.com/product/ar-15-arm-brace-blade-clamp-style-for-round-pistol-buffer-tube/