surundo Whoop 4.0 Silicone Sport Band Adjustable Waterproof

surundo Silicone Sport Band is a soft, adjustable replacement wristband designed to securely hold the Whoop 4.0 tracker during workouts, swims, and everyday wear.

If you want a lightweight, washable strap that keeps your Whoop 4.0 comfortable and stable through sweat, showers, and long days, this surundo band fits wrists from 5.9" to 8.26" (150–210 mm) and offers a breathable, skin-friendly silicone build. It’s tailored for active users who need a simple, tool-free swap for their tracker without sacrificing durability or daily comfort.

How does this band keep the Whoop 4.0 secure during activity?

The surundo band uses a snug, form-fitting channel and precision cutouts that cradle the Whoop 4.0 module while allowing one-click removal when needed. The closure stays locked during vigorous motion so the tracker won’t slip or fall off.

• Form-fitting silicone channel designed for Whoop 4.0 module stability
• Secure clasp system that resists accidental release during exercise
• Precision cutouts let you access sensors without dislodging the tracker

What materials and comfort features does the strap offer for all-day wear?

This band is crafted from soft, high-quality silicone that’s both flexible and breathable, reducing skin irritation during extended wear. The supple material is lightweight and quick-drying for post-workout comfort.

• Skin-friendly silicone with a soft, smooth finish
• Lightweight and stretchable for a natural wrist feel
• Washable and quick-dry for hygiene after sweaty sessions

Will the band fit my wrist and how easy is installation?

The surundo strap covers a wide wrist range (150–210 mm) and uses an adjustable fit system so most men, women, and teens can find a comfortable setting. Installation and removal are tool-free, letting you swap bands in seconds.

• One-size-adjustable design fits wrists from 5.9" to 8.26"
• Quick, tool-free installation with one-click disassembly
• Size adjustments are simple and secure for daily wear

Is this band suitable for sports and water activities?

Yes—the surundo silicone strap is built for active use including running, cycling, swimming, hiking and gym workouts. Its waterproof silicone and secure fit make it a reliable companion for outdoor and aquatic activities.

• Water-resistant silicone tolerates swims and showers
• Durable construction resists wear from frequent activity
• Designed to stay comfortable during endurance training and sports

Who is this for: The surundo Silicone Sport Band is ideal for active Whoop 4.0 users who want a durable, comfortable replacement strap that’s easy to install and maintain. It suits athletes, fitness enthusiasts, commuters, and everyday users who need a breathable, washable band that fits a broad range of wrist sizes. Note: surundo replacement bands are aftermarket accessories and are not affiliated with, endorsed by, or tested for compatibility by WHOOP.