Tried them on my 7800lb 35ft trailer for the first time in 4 days. And I was pleasantly surprised! Having just rolled the first two times on this newly purchased trailer I wanted to see if there was a noticeable difference and there certainly was. Especially when rocking, which sometimes annoys larger units. Good investment for the money and very easy to install. Tools are not required. The next test will be durability, but they appear to be well made from durable materials.