RevereSportWaterproof Samsung Galaxy S20 Ultra Running Armband. Sports Phone Case Holder for Runners

Will this fit older samsung phones e.g. s6 with/without a slim case? thanks.

Will this product count your steps correctly

Will this phone fit in the phone holder with a convertible otter box defender case on it? I know it would be tight but could you squeeze it in?

Will this work well for an S21 Ultra with a case sized 6.63 x 3.1 x 0.6 inches?