Extremely accurate and helpful that you get 2 scales for guitar and 2 for bass."Made in USA' is a big plus in my book; that's why I bought these. However, I was somewhat skeptical of how straight and flat these were, especially for the price compared to another well-known brand. I work in a calibration laboratory, and have access to a certified granite surface plate with a flatness accuracy of <200 microinches. Both the Guitar and Bass Notched Straight Edges were completely straight and flat, without any rough edges. They seem to be the same size and shape as the other, much more expensive brand. The only difference I see is they are made of aluminum instead of stainless steel. For the price, these are a bargain!Great product, works very well, but feels a bit overpriced at the end of the day for a notched straightedge. Can't complain much as when it comes to our special instruments the precision is worth it.It’s versatile and solid construction. Do you make true fret rockers as well? Awesome tools.GREAT product!! I got both the guitar scale and bass scale double pack and they arrived earlier than expected. As soon as they came I checked them against my good straight edge and these are dead level and straight! A great investment for anyone working on their instruments.Have been needing to do setups on my collection and this set is perfect for most of them. Able to check the neck on my 6 string electrics as well as my 4 and 5 string basses. This is my first set of neck straight edges so don't have anything to compare them to, but since they are made in the USA had to give them a go first. Love them and plan to buy from this company again for other guitars with different scale lengths.Shipped in rigid cardboard tube, sealed at both ends, stamped "DO NOT BEND" in large red block letters on the tube exterior. Both straight edges wrapped in plastic, well-machined and notched for intended use on most popular make guitars and basses. Quite straight, great value!They arrived in a shipping tube to keep them from shipping damaging. Well made aluminum. Notches are for Gibson, Fender and a few of the other guitars I have. I use them for checking guitar/bass neck straightness when changing the strings.