If you are looking for replacements, Rotochok has sizes which accomodate down to 5/8" spacing between tires. I have been very happy with ours. You can order replacement plates if the spacing changes, so that you don't have to order a whole new set of chocks. That is what we did when we went from our previous trailer to our current fifth wheel. The spacing was different and I just ordered replacement plates. I called Rotochok with my new spacing and had them within three days. Very good quality product.
Glenn & Beth (Dad & Mom)
David & Audra (12 year old twins)
2006 Dodge Power Wagon (Adventure & Tow Vehicle)
2006 Rockwood 8281SS (Home away from Home)