O’Neill Men’s 4/3mm HyperX Stitchless LTD Chest Zip

Overview

The O’Neill Men’s 4/3mm HyperX Stitchless Chest Zip is O’Neill’s answer to the old problem of cold water creeping through stitched seams. Instead of needle holes, it uses Stitchless Seam Technology (SST): triple-glued seams sealed on the inside with TB3X tape and on the outside with an 8mm silicone-based urethane Fluid Seam Weld. The result is less water getting in, more heat staying where you need it, and less fatigue over a long session.

It’s cut from TB3X (TechnoButter 3X) neoprene throughout, O’Neill’s pre-stretched, featherlight material, with a chest zip, a 360° anti-flush barrier and a hidden key pocket. In 4/3mm it’s built for a South Island winter: O’Neill’s own wetsuit guide says most New Zealanders wear a 4/3mm steamer in winter. Think frosty dawn paddles at Mangamaunu with fresh snow on the Seaward Kaikōura Range, or a long southerly-swell session off the Kaikōura coast when the water has a proper bite.

Features

• Stitchless Seam Technology (SST): triple-glued, fully sealed seams with no stitching holes, designed to minimise water entry and preserve core temperature
• Exterior Fluid Seam Weld: 8mm silicone-based urethane seal over a triple-glued, blind-stitched interior for watertight, durable, flexible seams
• Internal seam tape: 0.5mm split-neoprene TB3X tape on all seams, for another barrier against water and a longer seam life
• 100% TB3X (TechnoButter 3X) neoprene: pre-stretched with a featherlight ENVY foam rubber core for light weight, softness and stretch
• Chest zip entry using O’Neill’s FUZE system: a free-floating zipper panel for easy on and off
• 360° anti-flush barrier wraps around the inside of the neck and chest entry, acting as a second seal, with drain holes so trapped water can escape
• Double seal collar: a double layer of neoprene for extra comfort
• Minimal seam design: larger panels and fewer seams for flexibility, fit and durability
• Hidden key pocket in the right leg, below the knee
• Conscious materials: every Hyper Series steamer saves more than 0.5kg of plastic, with recycled oyster shells replacing calcium carbonate in about 10% of the neoprene, plus eco carbon black from scrap tyres, limestone-based neoprene and solvent-free lamination

Specifications

• Brand: O’Neill
• Model: HyperX Stitchless Chest Zip (style WST6C8MA)
• Gender: Men’s
• Thickness: 4/3mm (4mm body, 3mm shoulders and arms, per O’Neill’s wetsuit guide)
• Neoprene: 100% recycled TB3X (TechnoButter 3X)
• Seam construction: Stitchless Seam Technology (SST), triple-glued with internal TB3X tape and external Fluid Seam Weld
• Entry: chest zip (FUZE chest zip)
• Collar: double seal collar with 360° anti-flush barrier and drain holes
• Key pocket: hidden, right leg below the knee
• Type: long-sleeve, full-length steamer
• Colour: Black (per O’Neill’s listing for WST6C8MA)
• Sizes: S, M, MT, L, LS, XL, XLS
• O’Neill men’s size guide (height / weight): S 173-178 cm / 61-70 kg; M 175-186 cm / 68-79 kg; MT 185-191 cm / 73-82 kg; L 178-190 cm / 77-86 kg; LS 171-177 cm / 73-82 kg; XL 180-187 cm / 86-95 kg; XLS 174-179 cm / 82-91 kg
• Fit tip: wetsuits are sized by height, weight, chest and waist; if you’re between sizes, check O’Neill’s full chart before ordering