Es un accesorio para crocks, en mi caso, las zapatillas de mi hijo eran de "marca blanca" y sirven igual para poner en el agujero. Widest adjustment still 3/4" too short so unable to clamp on securely to rails. Got them today, and it?s all we are waiting on to leave. They were either going to rip apart or not fit. Loving it. ) So I know Ive reviewed 1 of these elsewhere, but I love this product & its a few months later, so here goes. Oh well, maybe next prime day amazon ??. Using this software, you can do all of the following with ease:- Fine tune specific audio settings to your liking. The radio reception for adequate, given that we live in an area that generally has poor radio signal. They are sturdy and well made.