The Favero Assioma DUO-Shi Power Meter consists of two pedal spindles that are installed into your current Shimano SPD-SL pedal bodies. The DUO-Shi is compatible with Shimano PD-R8000, PD-R7000, PD-6800, PD-R550 and PD-R540 pedal bodies. Unfortunately, the DUO-Shi does not work with DURA-ACE pedals as they use a different axle design and are therefore not compatible.
Favero Assioma DUO-Shi Power Meter Spindles