These Engineer's Squares are guaranteed to meet, or exceed, the British Engineering Standard BS939 of ±0.0005" per linear inch for squareness. This is an extremely high standard for setting up industrial machines, which will be more than enough accuracy for your workshop.
The boxed set of four is a convenient way to acquire a range of the most useful sizes, and get a very nice fitted wood storage box at the same time. The set includes 2”, 3”, 4” and 6”. They come at a saving over the cost of the individual sizes.
However, you can buy the 3” and the 6” individually (the 2" & 4" sizes are not sold separately). Please review the price-line descriptions.