Alternator Flat Mount is an adjustable dropout system designed to offer flawless functionality with flat-mount brakes installed. The dropout plates move back and forth on the frame, controlled with a captive barrel nut and screw for a minimal appearance. - Compatible with frames designed for the Alternator Flat Mount standard - Allows the rear axle to be adjusted through a 15mm range - Thru-axle diameter = 12mm; thread pitch = 1.5 - Note: This part number only includes a single Alternator Flat Mount plate - Uses Salsa 465 replaceable derailleur hanger (FS2322), sold separately. Also requires Salsa Axle Stud kit (FS1181) - Hardware kits (sold separately) must always be paired with the style of dropout plates being installed on the frame