Not bad at all for the price. You'll probably want to replace the two screws that come with it -- they are not smooth -- but have sharp edges to them.  It'd be a 4 or 5 star product otherwise.

I'm keeping them and replacing the screws as it isn't worth the hassle to return them and order another pair from another vendor.  Details below.

One thing to watch out for is the two screws at the top holding the arms into the glasses frame.  The screws aren't the best quality as there is a sharpness to them when you run your finger over it.  They should have been smoothed out more like almost every other screw in the world.  They still have a little sharpness to the edges where the screwdriver would be inserted.  That cause concern for people who'll use this with baby's that are still fussy with things on their face and will grab at them.