Small, cool and feature-packed, BOSS' TU-88 is a must-have for guitar and bass players on the go. It provides needle-accurate tuning, a metronome, and a headphone amp with speaker simulator for monitoring effects, including compact pedals. 

It has three tuning modes: chromatic, guitar, and bass, Flat Tuning function, and ACCU-PITCH verification with an audible beep. It has a built-in headphone amp that lets you tune, jam, and play your effects with headphones or direct recording. It also has a built-in metronome with selectable rhythmic patterns and volume control. The MIX IN feature allows jamming with an external music-playback device such as an MP3 player.

Features

• Needle-accurate tuning
• Built-in metronome with selectable rhythmic patterns and volume control
• Headphone amp with speaker simulator for monitoring effects
• Three tuning modes: chromatic, guitar, and bass
• Flat Tuning function
• ACCU-PITCH verification with an audible beep
• MIX IN feature allows jamming with an external music-playback device such as an MP3 player
• Tuning Range: E0 (20.6 Hz) to C8 (4,186.0 Hz)
• Reference Pitch: A4 (435 to 446 Hz)
• Tuning Accuracy: ± 1 cent
• Power Supply: Dry battery 6F22/6LR61 (9 V) type, AC adaptor DC 9V (PSA series; optional)
• Current Draw: 30 mA
• Expected battery life under continuous use (carbon): Approximately 8 hours (this figure will vary depending on the actual conditions of use)
• Accessories: Dry battery 6F22 (9 V) type (carbon), Owner's Manual, Leaflet ("Using the Unit Safely" and "Important Notes"), information
• Size and Weight (including batteries)
• Width: 5-9/16" (140 mm)
• Depth: 3-3/16" (80 mm)
• Height: 1-3/16" (30 mm)
• Weight: 0 lb. 7 oz. (0.2 kg)