FCS Harley Mid Tri QuadHarley Ingleby's Mid6 and Moe midlength models have become some of the most popular in this category. This is Harley's preferred fin set that's spec'd to work on longer boards and encourages a more progressive style of mid length surfing. HI also rides this set on in other hybrid shapes. The HI Mid set can be applied to any mid length with a Tri Quad setup. The set comprises the Reactor Large thruster template and the Performer Large quad rear fins.