4iiii


4iiii Viiiiva Heart Rate Monitor

£65.00 Sold out

Accurate heart rate tracking with Bluetooth & ANT+ connectivity — performance data you can trust.

TBC - Sold Out

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The 4iiii Viiiiva Heart Rate Monitor is your ultimate training companion, whether you're a seasoned pro or a dedicated fitness enthusiast. Engineered with precision power meter technology, it delivers industry-leading accuracy, ensuring highly dependable cadence data for optimal performance tracking.

The Viiiiva is designed to be durable yet lightweight, this heart rate monitor is compatible with ANT+ and Bluetooth head units, offering seamless integration with your existing fitness gear. With 3D power meter technology, it measures tri-axial strain on your crank arm, providing accurate and consistent data to help you train smarter.

With a battery life of over 100 riding hours on a 2032 coin cell battery, you can trust that the 4iiii heart rate monitor it'll keep up with your training demands. This innovative device features a battery status indicator via the 4iiii app, ensuring you're always aware of its power status. 

Key Benefits

  • Heart rate monitor
  • Compatible with ANT+ and Bluetooth head units
  • 100 riding hours
  • 2032 coin cell battery
  • 4iiii app available
Product Specifications
  • Measurement Type: ECG-Electrocardiogram
  • Operating Temperature: 0 - 50°C (32 - 122°F)
  • Storage Temperature: -20 - 60°C (4 - 140°F)
  • Battery Type: CR2032 lithium ion coin cell
  • Battery Life: 160hrs
  • Waterproof Rating: IPx7
  • Radio Frequency: 2.4GHz
  • Strap Length: 57 - 132cm (23 - 52in)
  • Length: 65mm (2.6in)
  • Width: 37.4mm (1.5in)
  • Depth: 11.2mm (0.4in)
  • Weight:
  • Communication Protocols: ANT+, Bluetooth®
  • Activity Save Duration: Up to 60hr
  • R-R Interval Unit: 1/1024s

  • COMMUNICATION COMPATIBILITY

4iiii Viiiiva heart rate monitors use both the ANT+ PWR and Bluetooth Smart Cycling Power Service standards, which makes them compatible with nearly every headunit, smartphone, or computer you wish to connect to. Check your recording device documentation for ANT+ PWR or Bluetooth Smart (also called BLE, BTLE, or BT4.0) Cycling Power Service capability.

Tip: A 4iiii Viiiiva can be used to record your workouts along with your heart rate.

Why We Choose 4iiii

We choose 4iiii because they’re at the forefront of cycling innovation, delivering world-class power meters and performance technology trusted by both pro teams and everyday riders. Their mission aligns with ours: making advanced training tools accessible, accurate, and reliable for all athletes.

  • Proven Accuracy – +/-1% precision power measurement for trusted performance data.
  • Innovation-Driven – Pioneers in lightweight, compact power meter design.
  • Ride Ready – Durable, weatherproof tech built for real-world cycling conditions.
  • Trusted by Professionals – Used by elite WorldTour cycling teams worldwide.

That’s why 4iiii is part of the North Sports collection — giving riders the tools they need to train smarter, push harder, and achieve their goals.

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