Very sturdy, more than MP5 Sliding Stock and 32 Degrees M4 Car Stock.
a little hard to attach. Have to hack off the back part of A5 back.
Although it was a pain to attach, its on and its very firm. It folds nicely also and does not hit the air tube from the frame to the cyclone like the MP5 Sliding Stock did. I was never able to close the Sliding Stock all the way. This Stock Folds all the way and locks. Its worth the money and hassle.
I would recommend this product, but if you dremmel, take a little off at a time for a good fit.