DIY a mobile power supply, you only need a battery, you can output 5-28 V for your mobile phone, MP3, MP4, very easy.in order to recharge electronic devices when the device needs 2-24V power supply, when it has - Lithium battery, this module can be directly step, up to 5-28V, solve problems.Product name: Step Up Boost Module adapterInput voltage: DC 2-24Output: DC 5-28 V, current Max: 2AFit connection: USB 2.0,printed circuit board Dimensions: 37 x 17 mm, 3.81 cm x 1.70 (0.67 (1.5 cm (L x L)Material: electrical parts, plastic, color: green / silverWeight: 5 g;Package contents: 1 x Step Up-Boost adapterOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.