r the surfer wanting to get critical and stay tight in the pocket of the wave or perform aerial maneuvers. Good for hollow, punchy beach breaks. Recommended for performance shortboards with a moderate to low rocker.

\r\n*Please Note: this fin is designed to be used exclusively with the FCS II Fin System, and will not fit in the traditional FCS Dual Plug System.","sku":"FCS:FREA-PC04-MD-TS-R","special_price":99,"stock_qty":2,"thumbnail_url":"//content.cavewire.com/host/boardcave-us/path/media/catalog/product/cache/1/thumbnail/75x75/e4d92e6aceaad517e7b5c12e0dc06587/o/s/osi_pimg_freapc04_char_0-655x655_1.jpg","type_id":"simple","url":"https://www.boardcave.com/fcs-ii-reactor-pc-tri-medium","visibility_catalog":1,"visibility_search":1},{"GEN_surffin_colour":"Blue","GEN_surffin_construction":"Performance Core Carbon","GEN_surffin_drive":5,"GEN_surffin_flex":4,"GEN_surffin_layout":"Five Fin","GEN_surffin_pivot":3,"GEN_surffin_release":3,"GEN_surffin_size":"M","GEN_surffin_system":"FCS 2","badges":["free_shipping"],"bc_answers":"5 fin set\nfins for open face and pocket surfing\nLost MB signature fin set","bc_fin_system":"FCS II","bc_kind":"fin set","categories":{"level0":["Shop"],"level1":["Shop /// Surf Accessories","Shop /// Brands"],"level2":["Shop /// Surf Accessories /// Surfboard Fins","Shop /// Brands /// FCS"],"level3":["Shop /// Surf Accessories /// Surfboard Fins /// Fin Brands","Shop /// Surf Accessories /// Surfboard Fins /// Fin Layouts"],"level4":["Shop /// Surf Accessories /// Surfboard Fins /// Fin Brands /// FCS","Shop /// Surf Accessories /// Surfboard Fins /// Fin Layouts /// Five Fin"],"level5":["Shop /// Surf Accessories /// Surfboard Fins /// Fin Brands /// FCS /// Reactor","Shop /// Surf Accessories /// Surfboard Fins /// Fin Brands /// FCS /// Shaper"]},"categories_without_path":["Shop","Surf Accessories","Surfboard Fins","Brands","FCS","Reactor","Shaper","FCS","Five Fin","Fin Layouts","Fin Brands"],"cavewire_barcode":9340935010523,"cavewire_product_brand":"FCS","created_at":1634855048,"free_shipping_eligible":1,"image_url":"//content.cavewire.com/host/boardcave-us/path/media/catalog/product/cache/1/image/400x500/e4d92e6aceaad517e7b5c12e0dc06587/f/c/fcsii_mb_medium_2021_tri_1200x_1.jpg","in_stock":1,"name":"MB PC Carbon Blue 5-Fin - M ","objectID":"11228","ordered_qty":0,"price":{"USD":{"default":185,"default_formated":"$$185.00","regular":185,"special":160.33,"special_from":"2026-07-08","special_from_date":1783468800,"special_to":"2026-07-10","special_to_date":1783641600}},"rand_sort_id":7656,"rank_most_popular":2207411,"rank_sale":1903623,"rank_whats_new":2969610,"rating_summary":0,"short_description":"

The FCS II Matt 'Mayhem' Biolos MB PC Carbon Blue 5 Fin medium sized signature template is a combination of drive and maneuverability. It is extremely versatile and can perform on both the open face and tight in the pocket. Ideal for medium to large surfers in the weight range of 65Kg - 80Kg / 145 - 175 Lbs.

*Please Note: this fin is designed to be used exclusively with the FCS II Fin System, and will not fit in the traditional FCS Dual Plug System.

","sku":"FCS:FMBM-CC04-MD-FS-R","special_price":160.3333,"stock_qty":1,"thumbnail_url":"//content.cavewire.com/host/boardcave-us/path/media/catalog/product/cache/1/thumbnail/75x75/e4d92e6aceaad517e7b5c12e0dc06587/f/c/fcsii_mb_medium_2021_tri_1200x_1.jpg","type_id":"simple","url":"https://www.boardcave.com/fcs-ii-mb-pc-carbon-medium-blue-m-5-fin","visibility_catalog":1,"visibility_search":1},{"GEN_surffin_colour":"Grey","GEN_surffin_construction":"Performance Core","GEN_surffin_drive":4,"GEN_surffin_flex":3,"GEN_surffin_layout":"Thruster","GEN_surffin_pivot":4,"GEN_surffin_release":3,"GEN_surffin_size":"L","GEN_surffin_system":"FCS 1","badges":["free_shipping"],"bc_answers":"fins for aerials and tight turns\nfins for punchy beach breaks\nFCS II Reactor tri fins large","bc_board_types":"shortboard","bc_fin_system":"FCS II","bc_kind":"fin set","bc_use":"beach","categories":{"level0":["Shop"],"level