This is a used item, but it's a great find. I purchased it on Amazon about 4 months ago, so it's in good condition. You can measure distances and the sweet spot ratio for each club during practice. Thank you. Golf swing trainer that can measure swing data in real-time. - Model: GOLF SWING TRAINER GST S GL - Measurement functions: Head speed, ball speed, swing speed - Display units: m/s, yd - Power supply: AA batteries - Condition: Used Thank you for looking.