Latest Facebook Lite 49 user agents:

User Agent Platform Device
Mozilla/5.0 (Linux; U; Android 4.3; en-gb; vivo Y18L Build/JLS36C) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30[FBAN/EMA;FBLC/en_GB;FBAV/49.0.0.10.69;] Android 4 Y18
Mozilla/5.0 (Linux; Android 5.1; VF-795 Build/LMY47D; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/44.0.2403.117 Mobile Safari/537.36[FBAN/EMA;FBLC/pt_PT;FBAV/49.0.0.10.69;] Android 5 Smart Speed 6