Our Filson x Birdwell swim trunks have ample built-in stretch providing completely unrestricted ease of motion. Crafted with Birdwell’s proprietary SurfStretch™ and SurfNyl™ fabrics, they’re quick-drying, lightweight, and roomy–ideal for the beach, summer alpine hikes, or warm-weather fishing. Birdwell has been building the best board shorts in the business since 1961, when Carrie Birdwell transformed her Santa Ana home into a sewing room and became one of the pioneers of clothing engineered for beach life. Sixty years later Birdwell still runs their business with the same principles as Filson does–manufacture purpose-built products, craft them with the best materials and construction, and stand behind them without fail. The base fabric for these shorts is Birdwell’s SurfStretch, a 90% spandex/10% nylon blend that provides unparalleled freedom of motion and is quite durable. The seat is reinforced with SurfNyl, developed by Birdwell to mimic the strength of a spinnaker sail while being softer against the skin and much more flexible. Sewn with double-needle stitching they’re built for countless seasons of warm-weather action. The right leg features a button-flap cargo pocket, and each hand pocket hides a small internal pocket. Adjustment tabs in the waist provide the security of a belt so you can dive in with confidence. The fly and waistband secure with mil-spec buttons.