Book: Primary Weapons.
City foundries produce a wide variety of weapons in an attempt to anticipate Guardians' ever-changing needs on the battlefield. But no Guardian can carry all guns at all times.
Enter the Boolean Gemini. Designed by a think tank of Guardians and foundry representatives, the Gemini was designed to be two guns in one, with a flexible design that allows Guardians to toggle between distinct combat styles for maximum efficiency.