The standard spool for consumer and business use. It was used by a number of other recorders based on Armour's technology and patents, including Webster-Chicago, the Dynaport (from William Lear), Majestic and Silvertone, among many others. Silvertone wire recorders were manufactured by Colonial Radio of Buffalo, NY for Sears, which sold them under its Silvertone brand. The spool held 7350 ft. of .004 in. diameter wire. In 1947 a spool like this one sold for around $4. Cases were either metal or cardboard.

Note the label "Armour Standard" on the lid of the metal case in image 2.