I'm sure these will serve a great purpose one day.  it turned out that they don't work where I intended to use them (my fault for mis-measuring, not the product's fault) so I haven't had a chance to see how functional they are, or how they stand up to regular wear & tear, which is why I couldn't give more than 4 stars.  but they appear to be solid and well made, and I love the idea of them.