The machine they had been using previously was the UP-8S, the predecessor to the UP-10D. Due to its aging, they considered purchasing a new welding machine and gathered information online, but after considering the price and intended use, they found it difficult to find a model that met their requirements. Furthermore, many sign manufacturers in the area had already installed the UP-10D, so they ultimately felt this was the machine for them and purchased it.
The key specification requirement for the selection was whether it was possible to weld on diagonal or narrow parts. Letter signs often have irregular shapes, so a model with a flexible gun would be easier to use. Also, the design that makes it easy to weld on the edges of box-shaped structures was a major deciding factor in terms of workability.