smart watch cex

hi I had a smart watch mi band 6 but course with button pop wrist band it easy come off and gone,

now I just need to do steps, and accurate heart weight when I am at gym etc

my old mi band seemed quite delayed of detecting walking also , like 6 mins after you walking and like rub / burnt marks from it

now it to track steps and why I am at gym ,so tread mill and weights etc,

I been looking at some Huawei watch 2 ,etc and lots on cex, budget 50 or lower, Android phone ‌

many thanks