I've used several of those. They are a Hanger 9 product and are for sale at my LHS. The straps seem to hold OK, although they add too much weight in my opinion.

By the way, the metal this mount is made from is soft and easily filed. I removed the mounting pads with a file and drilled & tapped mounting holes on one of mine to save weight.

Now that I've read the comments in the preivous post I may replace them.