A step up from Shapers famous SX Quad Rears, designed for heavier surfers requiring more control or for wider tail boards that feel loose as a quad set up. Compatible with FCS II Fin Systems Specifications: QRS: Small – Base: 96mm / 3.80” Depth: 99mm / 3.90” Sweep: 31° Foil: 80/20 QRM: Medium – Base: 98mm / 3.85” Depth 100mm / 3.93” Sweep: 31° Foil: 80/20 QRL: Large - Base: 101mm / 3.98” Depth: 106mm / 4.17" Sweep: 31° Foil: 80/20 Construction - CORELITE: A durable, lightweight fin construction with a progressive flex pattern and overall medium level of responsiveness. A good fin choice for surfers starting on fiberglass fins as the flex pattern is more forgiving, or for surfers wanting a more dynamic feel. The construction consists of Hex-Core Foam insert, Fiberglass and Polyester Resin.