This bluetooth keyboard have lithium  battery inside, you won’t have the trouble to change battery. Once the keyboard was charged, this keyboard can standby for over 2 months.This bluetooth keyboard specially designed for smart phone, a small bluetooth keyboard can be set in pocket.This bluetooth keyboard can work with Nokia smart phone that work with Symbian S60V2 S60V3,and even S60v5. Also can work with Windows Mobile 5 or above version , like Windows Mobile 6.After jailbroke, and down program BTstack keyboard(this will cost $5), this keyboard can work with IPHONE 2G & 3GS.And this keyboard can work with Windows 98 SE or above version , PC mother board with bluetooth receiver, and also APPLE MAC os with bluetooth receiver.This bluetooth mainly designed for at the present time touch screen smart phone, because touch screen smart phone without a real keyboard ,it is discommodiousness for typing letter through virtual keyboard.When you install this bluetooth keyboard, you can type letters, numbers, symbols quickly like you are typing them on you PC. Character:Operate Freq: 2.4GHzBluetooth version: 2.0Operate current: less than 2mAStand by current: less than 1.2mASleep current: less than: 0.2mAOperate Range: over 10 metersStorage temperature: -40 celsius degree ~ +125 celsius degreeDimension: 113mm(L) X 62.3mm(W) X12.3mm(H)Net weight: 67.5+-2 gramsGross weight: 138 gramsspackage size:189X125X22mmThis product can operate with the following smart phone thar work with Symbian system:For SymbianS60V2: Model list: Nokia 6260, 6630, N70, N72, 7610, 6670, 3230, 6680, 6681, 7710 and N90 etc.Take dirver  Symbian _ S60_ 2nd.sisFor SymbianS60V3: Model list:  Nokia 3250,5500, 6210, E50, E51,E60, E61,E61i, E65, E70, N71, N73, N77, N80, N80 Internet Edition, N91, N93,N92and N93i etc. Take driverSymbian _ S60_1_30.sis. For SymbianS60V3.1:Model list:  Nokia N76, N77, N81, N82, N95, E63, E71, E66,  E90, 5700 XpressMusic, 6110 Navigator,     6120 classic and 6290 SAMSUNGG810, G818, 400, i408, i450, i458, i550, i558, i560, i568, i8510, L870, L878 etc.Take driver  Symbian _S60_31.sis.For SymbianS60V3.2: Model list:  Nokia5630,N78,N79, N86, N85,N96,E52, E72, E75, 6730C,6720C,5730XM,5630XM, 6210 Navigator, 6220 classic, 5320 XpressMusic and 6650 etc.Take driver Symbian _S60_32.sis.All the above driver were contain in the attach disk.