We recommend Polar FT60, Polar M400, Polar A300 

Polar Ft 60

User Manual

https://support.polar.com/e_manuals/FT60/Polar_FT60_user_manual_English/ch01.html

Youtube Tutorial 

https://video.search.yahoo.com/yhs/search?fr=yhs-sz-001&hsimp=yhs-001&hspart=sz&p=polar+ft60+instructions+youtube+video#id=2&vid=92a7179b03b94667ddd59a1f5227aca9&action=click

The Polar M 400

User Manual

https://support.polar.com/e_manuals/M400/Polar_M400_user_manual_English/Content/Introduction.htm

Youtube Tutorial 

https://video.search.yahoo.com/yhs/search?fr=yhs-sz-001&hsimp=yhs-001&hspart=sz&p=polar+m400+tutorial+youtube+video#id=4&vid=f9ce402168fd04858a83134b422aea12&action=click

Polar A300

User Manual

https://support.polar.com/e_manuals/A300/Polar_A300_user_manual_English/Content/Introduction.htm

Youtube Tutorial 

https://video.search.yahoo.com/yhs/search?fr=yhs-sz-001&hsimp=yhs-001&hspart=sz&p=polar+a+300+tutorial+youtube+video#id=54&vid=d1998ae5f5caef0f5e5847a06a252dbc&action=click

Polar M200

User Manual

https://support.polar.com/e_manuals/M200/Polar_M200_user_manual_English/manual.pdf

https://support.polar.com/e_manuals/M200/Polar_M200_user_manual_English/manual.pdf

Youtube Tutorial