<hi style=afpcap>The Huff-Daland/Keystone Light Bomber Series was ordered during the period of a decade with a variety of designations applied. Many were allocated as LB-10, -13 and -14 indicating Light Bombers, with the L prefix subsequently being abandoned in 1930. The B-4 was a light bomber produced by Keystone with 25 examples being ordered in 1932. Other variants included the B-3, B-5, B-6 and B-7.</hi>