Built for srams popular red groupset and compatible with all of srams road groupsets the sram red dzero power meter embodies 10 years of quarqs technology advances and adds new features such as dual bluetooth low energy and ant wireless data transfer the new qalvin ble app and compatibility with bb386evo bottom brackets features bluetooth low energy technology and ant wireless data transfer axcad no magnet 10k temperature compensation battery cr2032 200 hour battery li