Need a backup for your gym bag or travel? This official WHOOP 4.0 Battery Pack is ready to go! This is the portable battery pack that slides right onto your WHOOP 4.0 sensor so you can charge while you wear it. It is a must-have accessory for any WHOOP user to ensure you never miss a minute of data. • Brand: WHOOP • Compatibility: Designed exclusively for WHOOP 4.0 (Will not fit 3.0) Features: • Wearable Charging: Slides onto your strap for "on-the-go" charging. • Water-Resistant: IP68 rated (up to 1 meter for 2 hours). • Standard Input: Takes a standard USB-C cable to recharge (Note: Cord NOT included). • LED Indicator: Lights up to show charging status. • Condition: Excellent pre-loved condition. Tested and holding a full charge. • Note: This listing is for the Battery Pack only. It does not include the charging cable or the WHOOP sensor. Fast shipping from a smoke-free home!