This is a Gnutti Left Crank Arm branded for Bauer. It is designed for a special Gnutti splined bottom bracket, introduced in the beginning of 1950s. It uses a special fine splined axle an which the arms are secured by a flat headed screw, quite similar to the later square tapered bottom brackets. This is also a version with fluted arms.

Length: 170 mm

Pedal thread: standard 9/16" x 20 tpi

Compatible bottom bracket: Gnutti splined

Material: Steel (chromed)

Please note that just the left (non-drive side is included)