SIBOASI Electric Racket Stringing Machine S616Stable constant pull function, power on self checking, automatic fault detection function; 2. Storage memory function, four groups of pounds can be arbitrarily set for storage; 3. Set up four sets of pre stretching functions to reduce damage to the strings; 4. Knotting and pounds increasing setting, automatic reset after knotting and stringing; 5. Three level setting function of button sound; 6. KG LB conversion function; 7. Pound adjusting by "+, "