I used this rail to make a sliding platform for an entryway into a house from a garage. I located the crawlspace access under the platform so you can slide the platform out of the way to enter the crawlspace. This product worked perfectly for what I needed to accomplish.
I have the rails installed and operational for a couple of weeks with not issues. everything was as advertised, The guide rails were straight and true. The truck bearings move smoothly when a load is applied. Fit and finish are good.
The blocks could be better cast with better cut threading but overall seem to be pretty straight and strong. Using as guide rails for 10mm thick 410x410 aluminum plate for custom 3d printer. So far with about 20 hours of use on them they have tracked fairly well.
I was not sure what to expect at this price point. I am accustomed to paying many more times the price for similar product from our favorite "McM... " store. Anyway I am extremely pleased by the quality at this price point.I rarely leave reviews but had to for this product!
Ryder Becker 
