Replacement Square Top (ST) Fins for the Hobie MirageDrive 180 pedal systems. Version 1, compatible with early 2017 MD180 drives.
Hobie Miragedrive MD180 ST Fin V1, Part# 81500001 are not compatible with V2 MD180 drives. Version 1 MD180 were current during the early part of 2017 and was phased out soon after in favour of a simpler design. See MD180 V2 ST fin