Grubs Frostline Insulated Waterproof 5.0 Green Boot

FROSTLINE 5.0

FROSTLINE 5.0 is insulated and waterproof, with excellent grip, made for all-day comfort.

Key Features:

• 5MM INSU-FOAM ULTRA Provides all-round foot comfort and insulation.
• 6mm NITROCELL footbed Offers soft cushioning with a million microscopic nitrogen bubbles that insulate from cold surfaces.
• UNDERFOOT CHASSIS Delivers a sure-footed platform.
• HEXZORB technology Absorbs heel strike shock for daylong comfort.
• SUPERDRI lining Hard-wearing, moisture-wicking, fungus and rot-proof for odor control and comfort.
• TRAX outsole Designed for superior grip across surfaces; tread works with the natural motion of the foot.
• Comfort Rating: -20ºC to +20ºC

INSU-FOAM ULTRA

Most GRUBS® rubber footwear uses our self-insulating INSU-FOAM ULTRA bootie construction, which acts as a neutral medium between the wearer and the outside. This bootie is both waterproof and insulating, exceeding the long-term effectiveness of traditional membranes and lofted insulations. Our boots are waterproof to EN ISO 20344: 2004 5.7 standard.

We use a super stretch Chloroprene materialcommonly found in deep-sea dry suitsthat stretches up to 300% and is covered with a 4-way stretch knitted nylon jersey. This allows expansion in both width and height. As a laminate with SUPER-DRI moisture-wicking terry knit lining, the bootie stretches up to 150% while keeping your feet dry and insulated.

INSU-FOAM ULTRA has a fine micro-cellular structure that stops heat transfer. The air bubbles are so small that the material remains waterproof even at 3.5mm thickness. It is also super soft and bouncy, with a compression set of less than 7% (compared to 2025% for typical neoprene boots). Other materials like SBR (Styrene Butadiene Rubber) are stiffer and more prone to leaking.

5.0 TECHNOLOGY

The bootie is lined with moisture-wicking SUPER-DRI terry knit for dry feet. The 100% stretch allows it to fit most calves comfortably. Thanks to the temperature-neutral INSU-FOAM ULTRA, your feet will stay comfortable from 85ºF to sub-zero temperatures.

TRAX Sole

The TRAX sole features a DURAPRENE rubber outsole with HEXZORB technology, providing superior grip. Its tread is segmented into zones for Grip, Traction, Stability, and Brakingsupporting your movement in every step.

Sizing Guide:

Please note: Our Wellington boots have a 15mm allowance for wool blend/combination socks. We recommend buying the same size as your regular footwear. For half-sizes, consider sizing down due to the sock allowance.