Are these CHEAP rail guide SQUARES any good?

In-Depth reviews of woodworking products from China. In this episode: Four rail guide Squares! If you want to see a ranking among all the products, I tested over the last three years, visit my site: Here are all the direct links to the products in this video. Reviewed products: Fonson Tools Mini Square Fonson Tools Big Square Extension Kit Fonson Square Silver Mini Square Silver big Square Upgraded Parallel Guide system Episode 30 Information about the UJK products I used to make my doghouse and the orange bench dog lifters: