FROSTLINE 5.0
FROSTLINE 5.0 is insulated and waterproof, with excellent grip, made for all-day comfort.
Key Features:
- 5MM INSU-FOAM ULTRA Gives all-round foot comfort and insulation.
- 6mm NITROCELL footbed Soft cushioning for an athletic shoe feel, with nitrogen bubbles that insulate from cold surfaces.
- UNDERFOOT CHASSIS Provides a sure-footed platform.
- HEXZORB technology Absorbs heel strike shock for day-long comfort.
- SUPERDRI lining Wicks moisture, prevents sweat build-up, and is fungus and rot-proof.
- TRAX outsole Superior grip on varied surfaces, with tread designed to follow foot movement.
- Comfort Rating: -20ºC to +20ºC
INSU-FOAM ULTRA Technology
Most GRUBS® rubber footwear uses our self-insulating INSU-FOAM ULTRA bootie construction, acting as a neutral barrier between the wearer and external conditions. Its both waterproof and insulating, exceeding the long-term effectiveness of traditional waterproof membranes. Our boots meet the EN ISO 20344:2004 5.7 waterproof standard.
Constructed using super stretch Chloroprene (commonly used in deep-sea dry suits), the boot material stretches up to 300% and is laminated with a 4-way stretch nylon jersey. This allows it to expand in width and height. As a laminate with SUPER-DRI terry knit lining, the bootie can stretch up to 150%, ensuring comfort and fit.
Its fine microcellular structure stops heat transfer. Even at 3.5mm thickness, it remains waterproof. The material is soft, bouncy, and long-lasting, with a compression set of less than 7% (compared to 2025% in typical neoprene boots). In contrast, SBR (Styrene Butadiene Rubber) foams used by others are stiffer, degrade faster, and are more likely to leak.
5.0 TECHNOLOGY
The bootie is lined with moisture-wicking SUPER-DRI terry knit, offering 100% stretch for a calf-hugging fit. The temperature-neutral INSU-FOAM ULTRA keeps feet comfortable from 85ºF to sub-zero conditions over long periods.
TRAX Sole
The TRAX sole uses DURAPRENE rubber with integrated HEXZORB for superior grip. The outsole is divided into functional zones to optimize Grip, Traction, Stability, and Braking, in sync with foot motion.
Sizing Guide:
| UK Size | Boot Height (mm) | Calve Width (mm) |
|---|---|---|
| UK 3 | 370mm | 400mm |
| UK 4 | 370mm | 400mm |
| UK 5 | 375mm | 410mm |
| UK 6 | 380mm | 410mm |
| UK 7 | 385mm | 420mm |
| UK 8 | 390mm | 420mm |
Please note: Our Wellington Boots have a 15mm allowance for wool blend/combination socks.
We recommend purchasing the same size as your regular, comfortable footwear. For half sizes, we suggest sizing down due to the allowance.