Made out of aluminum, plenty long and fit and finish is excellent. I really like the enlarged front finger rest, you can tell it's a very well thought out design. Considering all this I am not sure why they decided to do the clamp geometry and spring hole location the way that they did. When comparing to the MDT extended and stock CZ release the engagement between the magazine and the head of the release is very different. This makes magazines feel loose and rattle. The most noticeable thing is the hole location for the spring. On the other two options the whole location is significantly lower relative to the head and makes the fit much tighter on the magazine. This is the case with polymer and l3i aluminum magazines. It doesn't seem to impair the function at all, the bullets load fine, but for a premium part it's so close to being perfect that it' s very sad that it's not.

Worked as advertised. Appears to have no problems so far.

Purchased two. One for a 457 and one for a 512. I called and asked about compatibility with the 512. I was told they did not know but if I tried and it did not work I could return. Well it worked great in the 512 as well.
Great product. Great improvement to both rifles.

Sorry, ignore previous post.
Fit perfectly. Slightly longer than factory one.