BEST BRASS e-brass III for French horn EB3-FHR International Version Overall length: 182mm, width: 66mm, weight: 110g Mute level:-30dB about Function: digital echo, headphone volume Input : AUX-IN (stereo mini jack), PHONE (mini stereo jack), LINE OUT (stereo mini jack) Accessories: stereo headphones, Karaoke CD (mini score with), connecting cable (stereo mini-jack / stereo mini-jack)  AAA batteries (not included) requires two. (Recommended. Alkaline batteries)