A:AnswerThe watch has a built-in heart rate monitor so you won't need a separate monitor. However, it will pair with an external monitor if you're serious into always having the most accurate HR measurements under all conditions - like swimming.
A:AnswerThe Best Buy system says it will be in stores 3/30/16, and my preorder pick up date is 3/27/16.
Amazon and REI are saying much the same, and Garmin.com shows it as available.