Garmin HRM600 Heart Rate Monitor - XSmall - Small MFPN=11159392 This is a great option

This is a great option for beginners or juniors due to the smaller wheel keeping you closer to the ground and also a shorter shaft for increased maneuverability

compatible with most Shimano 3x7/8sp drivetrains

}SRAM XX Eagle T-Type AXS Wide Left Crank Arm with Power Meter Spindle - 175mm 12-Speed DUB Spindle Interface Carbon Black D1

8mm Color Purple

}Wheels Manufacturing BSA Bottom Bracket - DUB Spindle ABEC 3 Blue

Garmin HRM600 Heart Rate Monitor - XSmall - Small MFPN=11159392 This is a great optionHRM 600, the premium heart rate monitor, is built for data driven performance athletes. It provides accurate heart rate and HRV data plus running dynamics with step speed loss which helps runners improve their form when paired to a compatible smartwatch. After pushing hard, easily remove the module, and throw the strap in the wash. TECH SPECS Connectivity ANT+ BT Misc XS S