£130.00
Matt 'mayhem' Biolos's specialty quad fin set. High surface area quad keel set adds bite and control to hybrid boards with wide tails, without sacrificing pivoting capabilities.
Availability: Out of Stock – We understand the frustration when the product you're looking for is unavailable. At Down the Line Surf, we constantly update our inventory. New stock may be coming in soon. Give us a call on +44 (0)1736 757025 or submit your email below to be notified when new stock arrives. Thank you for choosing Down the Line Surf!

Matt 'mayhem' Biolos's specialty quad fin set. High surface area quad keel set adds bite and control to hybrid boards with wide tails, without sacrificing pivoting capabilities.

Ideal conditions
Open face, down-the-line waves, particularly good in point and reef breaks.

Board types
Modern fish and hybrid models with moderate-to-low rocker.

Fin material
Performance glass

Fin specs:

Quad Side
Base: 4.63" / 117.4mm
Depth: 4.79" / 121mm
Area: 19.27"² / 12432mm²
Sweep: 44.8º
Foil: flat

Quad rear
Base: 4.03" / 102mm
Depth: 4.40" / 112mm
Area: 12.63"² / 8150mm²
Sweep: 28.5º
Foil: 80/20

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.

UK Delivery for this product =
£3.95 for Royal Mail 48hr service.
£6.49 for Express Courier.

Generally all goods ordered before 1pm are sent out on the same day (Mon-Fri).

We offer a fast and efficient worldwide delivery service.

For International deliveries, the shipping will be calculated at checkout, together with any duties and tax. This ensures you have no unexpected charges when receiving your goods.. We guarantee you will have nothing extra to pay.

Check here for our full delivery information


Not happy with your product?

No problem at all!

You can return the product up to 30 days after purchase for a no quibble replacement or refund.
Simply fill out the returns form enclosed with your package and send back to us.
info@downthelinesurf.co.uk or ring one of the team on (01736) 757025

Please find our full Returns & Refund Policy here, and our Shipping Policy here. Customer Services can be contacted here.

If you have any questions about the FCS II MB Split Keel Quad Fin Set, submit the product question form below and we'll get back to you as soon as possible. Or give us a call on (01736) 757025.