The horn weighs 2.5 lbs. Its bell, crafted in heavy wall copper-plated brass, is 6.5 inches in diameter. The leadpipe is 0.421 "large bore" as manufactured by French Besson for Boosey & Hawkes, based on a classic 1890 Paris Exposition design. Its valves are top sprung monel pistons with metal interior casings and a lacquered brass exterior, as manufactured by English Besson based on a design by Couesnon & Company.
Farmer made a number of modifications to his Kanstul flugelhorn such as adding tuning triggers to the first and third valve slides and making custom valve caps inlaid with 1916-D Mercury dimes, an idea borrowed from symphonic French horn players of the era. Although weathered with age and oxidation, the name of the instrument's original owner is still visible, engraved on the flugelhorn's copper bell.
To expand the flugelhorn's timbral palette with additional tones and colors, Matheny uses a Jo-Ral tenor trombone bubble mute designed by Joe Alessi and an assortment of hats, bottles, mutes and plungers.
