DAB GO! App that works with radio receiver inside the battery pack. It works with radio interface without clumsy button on the case FM/DAB/DAB+/Internet Radio Built-in FM/DAB/DAB+ receiver turns your iPhone 4 a radio player in serviced area. it is the only DAB receiver that has passed iPhone"s accessory power requirement.1500 mAh Liethium-ion battery App that works with radio receiver inside the battery pack. It works with radio interface without clumsy button on the case. Charging Wizard TM ( Patent-Pending) Intelligent power management system to monitor your iPhone 4"s power capacity DAB/DAB+ Slide Show Display iRis is world"s first portable DAB receier that supports color slide show. With iRis battery pack, your iPhone 4 is enriched by colorful radio. Specification Frequency Coverage FM 87.5 - 108 MHzDAB 174.928 - 239.200MHz ( Band III) Headphone socket 3.5mm dia, 16 - 32 ohms compatible Aerial System FM Headphone-lead aerialDAB Headphone-lead aerial Dimension 12.5(L) x 6(W) x 1.6(T) cm 4.9(L) x 2.36(W) x 0.62(T) in Weight 69g ( 2.43 oz)