Download Android KitKat 4.4.2 Firmware RK3288 TV Boxes with AP6335 WiFi Module fromhere or here. 


Update file name: rk3288_4.4.2_q8l_ap6335_v01_20141115
Archive size: 304 MB
Firmware file: update.img
Model: RK3288 TV Boxes with AP6335 WiFi Module
Boot version: 2.15
FW version: 4.4.02

Source