My former Sportline 330 was an excellent and 100% accurate instrument. This one is a totally different design and is useless. I never found out how accurate it is, because in the new design the reset button is in front of the device so you can't help but to accidentally reset it in the normal course of human motion. On the old one the reset button was inside its cover. This one has no cover. Useless. To add insult to injury, they don't tell you they changed the design, so it's a nasty little surprise when it arrives.