Not crazy about the single bearing on the y axis.. Also I'm always suspicious of non-branded rails (didn't see any mention of the brand in the description). Spk64 over on CNCZone found a supplier of profile rails and bearings on aliexpress (Three Ring Precision Machinery) for dirt cheap. He ordered them and ran some tests.. Basically they're not hardened to the same specs as the big name brands (THK, NSK etc) and will surely fail much sooner. Funnily enough they're fully compatible/interchangeable with the THK HSR line (basically a complete copy, but to a lower spec)... Not saying it won't work well for hobby use, but just something to consider.

Devin