For comparison I used a friends makita rails, no clamps for full length rips on mdf and they dont budge at all. The product does not work. I noticed the side of the clamshell was open. Not worried about it falling at all! I could not return them simply because I washed them before I tried them on assuming they were going to be the same. Excelentes sandalias para una tarde tranquila. Ive never been disappointed with Razer. And the plastic construction (see again under quality) actually has one plus in that it keeps the headphones light. Im a 9 1/2 and the large is like a size 10 so they are a little long at the back but I dont notice it at all. Theyre just half the price.