how to use a guitar tuner

{"cid":"91225860","title":"Oxford Fabric Dual Use Backpack Handheld Guitar Case Instrument Storage Gig Bag 40 41 Inch","imgUrl":"https:\/\/img.chinax.com\/nimg\/2b\/d5\/8c7fa3229e5d6e5c646c14b63a0c-200x200-1.jpg","attrs":{"Price":"$ 2.44-2.61\/pieces","Brand Name":"Tenghai","Model Number":"CB-10","Delivery Time":"10-15 work days","Product Name":"Guitar Bag","Carry Way":"Hand Carry \/ Backpack Carry","Front Pocket":"33*26cm","Place of Origin":"Guangzhou","Payment Terms":"T\/T","Net Weigh":"550g","Product Dimensions":"42*10*105cm"}}

{"cid":"91179284","title":"AAAA handmade OOO shape all Solid ebony wood acoustic electric guitar","imgUrl":"https:\/\/img.chinax.com\/nimg\/44\/46\/70f85cd61c4b6d68863175926cb4-200x200-1.jpg","attrs":{"Price":"750-$850\/pcs","Brand Name":"Grand","Model Number":"OOOD","Minimum Order Quantity":"1pcs","Delivery Time":"20 days","Certification":"CE, ROHS, FCC","Place of Origin":"China","Payment Terms":"TT, Paypal, Western Union, , LC","Supply Ability":"1000pcs\/month","Packaging Details":"Single Box with EPE Foam","Guitar Name":"OOO Europe spruce top acoustic guitar","Body":"Solid ebony","Neck":"Mahogany","Fretboard":"Ebony","Back\/Side":"Solid rosewood","Type":"AAAA acoustic guitar"}}