I used a rubbish Silverline one for several years and then adapted it for my table saw as shown. Works a treat.
The nylon featherboard can be locked anywhere on the rail and the rail itself is surprisingly stable in use and clips off in seconds.
I've just been to Lidls and bought the guide. It's really a clamp, maximum 1010mm, but can be used as a straight edge to run a circular saw/jig saw alongside. It's not a track saw guide as such, nothing to lock a saw onto. But for £9.99 it'll make a good tool for DIY.
Cheap version of the trend clamp n guide gizmo that has been around for many years. Never used one for clamping but the trend ones make a useful straightedge to run a router against.