Peterson 490-ST AutoStrobe Tuner with Stretch Tuning device.  With manual and book: Piano Servicing, Tuning, and Rebuilding, Second edition, isbn 9781879511033Our Donor was using this in their tuning business and told us that it is in good working order. He had 2 and only needs 1 now. The unit is clean and does turn on when plugged in.  However we have no technical knowledge about this device and are selling it as is. Double boxed for safe shipping! Item donated for the benefit of ReplaysA Non-Profit, Local, Quality Resale shop that benefits the UVM Medical Center Patient Programs. We are located in the Blue Mall on Dorset Street in South Burlington, Vermont. Donations of any season or category are accepted daily!  Store Hours are Monday 10am to 4pm, Tue-Sat 9:30am to 5:30pm.Please look carefully at the photos before bidding, and if you have any questions about the item(s) please email us. We will try our best to answer your questions. We are not experts and try our best not to omit or hide any necessary details.NO RETURNSABOUT THE ITEM:Capable of handling “stretched” interval tuning, this is the instrument technician’s most valuable tool. The Peterson AutoStrobe 490ST offers a vast array of selectable “stretched” tuning options, including pianos of all types. Enjoy the instantaneous response times that only a Peterson can deliver and the relative tuning display of any audio source to 0.1 of a cent (1/1000 of a semitone) accuracy!With the Model 490-ST, students, technicians, and musicians of all levels can utilize automatic (hands-free) note selection for absolutely the most accurate tuning of any instrument. Key features including real-time display of intonation to improve performance and listening skills while playing as well as mutable throughputs for in-line (yet silent) tuning during performances round out the package.