I just purchased this extension for my original 4000 table saw (purchased in the early 2000's) and it is perfect in my view. The assembly was extremely easy and the performance exceptional. I delayed buying this thinking that a separate roller stand was sufficient but this assembly has made things so much easier. First off the extension is always there and not in the way when not needed but easily accessible when that little extra support is required. Secondly, this is a well manufactured component with a milled flat for the lock screw to bite down on, E clips on the rear rail for limits and a substantial steel work support rail. The mounting brackets are extruded aluminum offering more than enough strength and very easy sliding of the support in and out of the table (almost effortless). As far as some complaints of having to shim the support brackets for levelling and a problem with sag that is just not the case when I installed mine? The adjusting holes are all slotted making adjustments simple. This is a quality accessory and is highly recommended to anyone using a Bosch 4000 table saw.