INCLUDES DURA-ACE TRACK BOTTOM BRACKET BB-7700 MODEL NO BB-7700 SERIES DURA-ACE TRACK 7710 NJS 144mm PCD Series Average weight 173 Length 175 Spindle|Hollow pipe Spindle|OCTALINK Axle length/shell width (mm)|109.5|68 (BC1.37) Axle length/shell width (mm)|109.5|70 (M36) AND Stages Gen 3 single-sided Power L meter built onto Shimano's Dura-Ace Track 7710 arm. Available in silver and compatible with Shimano 7710 track cranksets. Accuracy: ± 1.5% Power meter housing: low profile design, with robust door interface Weight: Only adds 15g to base crank arm Battery Life: 200+ hours (coin cell: CR2032) when used as a single-sided meter Power range (Watts): 0 to 2500 Cadence range (rpm): 10-220 Water resistance rating: IPX7 RETAILS FOR $719