Features: 1. CNC aluminum alloy material; durable to use. With back clip; high concealment. 2. One-click recording; with delete function; play LED light indication. 3. ADPCM recording 192Kbit; optional voice-activated recording 50DB; automatic split recording; loop overwrite recording. 4. Recording for 25 hours in a row; standby for 30 days; 8GB capacity (storage recording for 90 hours). 5. Support MP3; WMA; WAV playback; support fast forward and backward playback. 6. With time stamp; the name of the recording file is named by time. Specification: Color: Black Size: about 5.2*2*1.2cm/2.05*0.79*0.47in Package Size: about 10*7.5*4.5cm/3.94*2.95*1.77in Weight: about 93g/3.28oz Recording format: ADPCM recording Recording bit rate: 192kbps Continuous recording: 25 hours Power supply: 3.7V 100mAh Package List: 1 * Recording Pen 1 * Earphone 1 * Data Cable 1 * Instruction Manual&nbsp;<img data-srcid="-" src="https://image.doba.com/dgd1-yNvkmtRrLcVi/x21-16gb-voice-recorder-mini-concealed-sound-one-click-recording-pen-mp3-player-with-back-clip-support-mp3-wmawav-playback.jpg" alt="dropship X21 16GB Voice Recorder Mini Concealed Sound One-Click Recording Pen MP3 Player With Back Clip Support MP3 WMA/WAV Playback" /><img data-srcid="-" src="https://image.doba.com/dgd1-zJDwhZHPUYbS/x21-16gb-voice-recorder-mini-concealed-sound-one-click-recording-pen-mp3-player-with-back-clip-support-mp3-wmawav-playback.jpg" alt="dropship X21 16GB Voice Recorder Mini Concealed Sound One-Click Recording Pen MP3 Player With Back Clip Support MP3 WMA/WAV Playback" /><img data-srcid="-" src="https://image.doba.com/dgd1-yMVvhTRLjYDI/x21-16gb-voice-recorder-mini-concealed-sound-one-click-recording-pen-mp3-player-with-back-clip-support-mp3-wmawav-playback.jpg" alt="dropship X21 16GB Voice Recorder Mini Concealed Sound One-Click Recording Pen MP3 Player With Back Clip Support MP3 WMA/WAV Playback" /><img data-srcid="-" src="https://image.doba.com/dgd1-mADdifHsUYVI/x21-16gb-voice-recorder-mini-concealed-sound-one-click-recording-pen-mp3-player-with-back-clip-support-mp3-wmawav-playback.jpg" alt="dropship X21 16GB Voice Recorder Mini Concealed Sound One-Click Recording Pen MP3 Player With Back Clip Support MP3 WMA/WAV Playback" /><img data-srcid="-" src="https://image.doba.com/dgd1-htDRmanPsYVl/x21-16gb-voice-recorder-mini-concealed-sound-one-click-recording-pen-mp3-player-with-back-clip-support-mp3-wmawav-playback.jpg" alt="dropship X21 16GB Voice Recorder Mini Concealed Sound One-Click Recording Pen MP3 Player With Back Clip Support MP3 WMA/WAV Playback" />