Installed the 'new' four step aluminum tread steps today. Tried yesterday but bar across the top would not allow steps to fit in. Today #1 son came by with his rotary cutter and we zapped off that cross bar. We had the four steppers installed in less that fifteen minutes. Seem to work fine except we need to do some work to allow them to fully deploy where we park. Can see where a support is needed on the second step from the bottom, but that is not an issue as we always put a support under the bottom step of the all steel ones.