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4iiii GRX RX810 Precision 3 Single Leg Power Meter
4iiii GRX RX810 Precision 3 Single Leg Power Meter
4iiii GRX RX810 Precision 3 Single Leg Power Meter
4iiii GRX RX810 Precision 3 Single Leg Power Meter
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4iiii GRX RX810 Precision 3 Single Leg Power Meter
4iiii GRX RX810 Precision 3 Single Leg Power Meter
4iiii GRX RX810 Precision 3 Single Leg Power Meter
4iiii GRX RX810 Precision 3 Single Leg Power Meter

4iiii GRX RX810 Precision 3 Single Leg Power Meter

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Backorder: This item is currently not in stock but is available to purchase today as a backorder. The expected availability date shown above is our best estimate as to when it will be shipped to you, but this date is subject to change based on our receipt of this item from its vendor. Shipping in the continental US is free for all backorder items (for international orders, our customer service team will contact you when the item is available to ship). Your credit card will not be charged until your item ships (Paypal requires payment up front, but you can cancel for full refund). Anytime prior to shipment, your backorder can be cancelled by contacting our customer service team.

The Lightest Power Meter On The Market

The 4iiii GRX RX810 Precision 3 Powermeter delivers industry-leading accuracy and reliability when you need it most. 4iiii's patented 3D Strain Gauge technology assures that the data you depend on will help lead you to your own personal best.

Packaged into a durable lightweight design and compatible with ANT+ and Bluetooth Smart headunits, the Precision 3 will help you train harder and smarter.

A ride-ready 4iiii Precision 3 includes and comes preinstalled on a brand-new GRX RX810 left-side crankarm, compatible with bottom brackets using the Hollowtech II interface.

Whether you are fighting for a Kona slot, spending countless hours on the indoor trainer or striving for a personal best — one thing is clear, success takes time. With up to 800 hours of battery life, +/-1% accuracy and weighing in at only 9 grams, the Precision 3 Powermeter will be your trusted training tool for years to come.


  • Hollowtech II left side crank arm with built-in 4iiii power meter
  • +/- 1.0% accuracy lets you collect training data with confidence
  • Accelerometer with gyroscope offers detailed cadence readings
  • 9g design is one of lightest crank arm-based meters on the market
  • 800 hours of battery life via replaceable CR2032 battery
  • Pair to the 4iiii app with ANT+ and Bluetooth SMART to transfer data
  • Available in 170-175mm crankarm lengths
  • Compatible with Shimano GRX series drivetrains
  • Power range: 0-4000W
  • Cadence range: 30-150RPM
  • IPX7, IPX5 waterproof rated
  • Sensor weight: 9g

B-Stock - This product has one or more B-Stock units available. These units can be purchased at a discount (see option select). B-Stock units were returned from other customers and may have missing or damaged packaging materials. These units are otherwise as new. The full manufacturer warranty applies. Click Here for more information.


Mfg PartNum: PML300-S17B00J 


Mfg PartNum: PML300-S17C00J 


Mfg PartNum: PML300-S17D00J 

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Reviewed 1/27/2023
by Jamie
Cycling Enthusiast
State College, PA
Value Rating
Overall Rating
Excellent power meter with plenty of clearance

Added this to my gravel bike, which I mostly ride on road. In order to fit wide tires, the chainstays on the bike flare out, leaving there to be little room between crank and frame. The new low profile 4iiii power meter fits just fine (the old one wouldn't)!

Otherwise, this power meter works like previous 4iiii power meters, which is to say, excellent. One thing to note, unlike previous versions, this doesn't support Chipolo features, so you can't use the power meter to locate a lost bike. I never used this feature (thankfully) on my other 4iiii PM, so I can't really I really miss it.

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