Download latest Android KitKat 4.4.2 stock firmware for Guleek H5 TV Box from here or from here. Photo gallery here.
Firmware details
Archive: guleek H5
Firmware image file: guleek_rk3188_h5_20141209
Model: Guleek H5 TV Box
Image file size: 330 MB
Platform: Rockchip RK3188
Model number: GLK-H5
Boot version: 2.09
FW version: 4.4.02
Build number:rk3188-eng 4.4.2 KOT49H eng.yanghui_test.20141209.125430 test-keys
SDK version: RK30_ANDROID$(PLATFORM_VERSION)-SDK-v1.00.00
Caution: Please do not update firmware unless you know what you are doing, you really want it or it is absolutely necessary. Firmware updates may occasionally have bad results, like bricking your device, temporarily or permanently. The firmware update process is done entirely at your own risk. Before attempting to update the firmware, back up your data.