3.5mm Female Jack to 1/4" Inch Male Mono Plug 6.3mm Adapter Miniature Mono Jack Female Nickel Plated Contacts 3.5 mm to 1/4 Inch Mono Plug Converter Head Phone 3.5mm mono jack 1/4 inch mono plug adapter To connect 3.5mm mono jack into 1/4 inchstereo plug Don't throw out those old headphones just because they don't fit your new stereo Get this mono 1/4 inch to 3.5mm mono adapter and they'll fit right in! Lifetime Warranty.