The 2INpower and INpower are both spindle-based power, with the difference being that the 2INpower is dual-sided and rechargeable, whereas the INpower is single-sided and powered by a AA battery. The 2INpower has strain gauges in both the crank arm and the crank spindle for precise, independent measurements.
The INspider, on the other hand, is spider-based, where the strain gauges are in the spider itself. Therefore, it takes the place of the MAS spider, using 110x4 chainrings exclusively. The aero crown is an optional accessory that smooths out the lines to make a more aerodynamic and aesthetically clean finish for aero bikes. The INspider is compatible with all of our current model cranks, including the ALDHU and VEGAST.