The product arrived quickly and undamaged despite the packaging being a little weak. The product is quite robust so survived the journey froim China OK.
Seems there has been an upgrade since earlier reviews as the rollers now have one way bearings, rolling freely in the feed direction but locking in the opposite (kickback) direction.
The feed direction markings on the product I received are correct and both rollers are inclined so as to guide the stock towards the fence.
The only thing these lack is a spring tension system that would allow you to run stock of varying thickness under them, once adjusted for your stock thickness these lock against the fence at that height . However, I imagine the rubber on the rollers will accommodate a very minor variation in thickness of the stock.
The Hongdui version has spring tension allowing the rolloers to ride along the stock as it is fed into the saw, however they are almost four times the price of these.
Comes with smaller M5 t nuts that are compatible with the 2020, 2040, 2060, 2080 style of aluminium t-slot extrusion.

Exquisite, solid, functional. Looking forward to using them on my router table fence, after modifying it to accomodate the necessary t-track. Unfortunately I will not be using them on my DeWalt table saw, as I do not want to modify the existing oem fence.