Seatec EXTREME sharkfin 6,35mm shaft double flopper

As EXTREME we mean a particular type of stem with recessed (single or double) wing. This is possible thanks to a careful milling process in order not to weaken the section near the flap. There are various models of Extreme fins: standard = stainless steel thickness. mm.0,8 length mm.74 heavy = stainless steel thickness mm.1,00 length mm.74 Before assembling the fin, they are tested for straightness on inclined surfaces. This is a rod made of 17.5 PH tempered stainless steel with a strong coefficient of elasticity and hardness (R = 160 kg / mm2).