Latest Opera Mobile 21 user agents:

User Agent Platform Device
Mozilla/5.0 (Linux; U; Android 8.1.0; itel W6001 Build/OPM2.171019.012; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/70.0.3538.110 Mobile Safari/537.36 OPR/21.0.2254.111724 Android 8 P33 Plus
Mozilla/5.0 (Linux; U; Android 7.1.2; Redmi Note 5A Build/N2G47H; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 OPR/21.0.2254.111920 Android 7 Redmi Note 5A
Mozilla/5.0 (Linux; U; Android 7.1.1; SM-N950F Build/NMF26X; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/65.0.3325.109 Mobile Safari/537.36 OPR/21.0.2254.111677 Android 7 Galaxy Note 8
Mozilla/5.0 (Linux; U; Android 7.0; E6553 Build/32.3.A.0.372; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/56.0.2924.87 Mobile Safari/537.36 OPR/21.0.2254.111920 Android 7 Xperia Z3+
Mozilla/5.0 (Linux; U; Android 7.0; 5047D Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/59.0.3071.125 Mobile Safari/537.36 OPR/21.0.2254.111678 Android 7 U5 HD
Mozilla/5.0 (Linux; U; Android 7.0; 4047D Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/67.0.3396.87 Mobile Safari/537.36 OPR/21.0.2254.111678 Android 7 U5 3G
Mozilla/5.0 (Linux; U; Android 7.0; 4047D Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/56.0.2924.87 Mobile Safari/537.36 OPR/21.0.2254.111678 Android 7 U5 3G
Mozilla/5.0 (Linux; U; Android 6.0; F3111 Build/33.2.A.3.81; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/51.0.2704.81 Mobile Safari/537.36 OPR/21.0.2254.112007 Android 6 Xperia XA
Mozilla/5.0 (Linux; U; Android 6.0; em_t8350_emmc Build/MRA58K; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/44.0.2403.119 Mobile Safari/537.36 OPR/21.0.2254.111920 Android 6 Unknown
Mozilla/5.0 (Linux; U; Android 6.0.1; Wileyfox Swift Build/MHC19Q; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 OPR/21.0.2254.111920 Android 6 Swift
Mozilla/5.0 (Linux; U; Android 6.0.1; SM-J510FN Build/MMB29M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/56.0.2924.87 Mobile Safari/537.36 OPR/21.0.2254.111920 Android 6 Galaxy J5 (2016)
Mozilla/5.0 (Linux; U; Android 6.0.1; SM-G935F Build/MMB29K; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 OPR/21.0.2254.111677 Android 6 Galaxy S7 Edge
Mozilla/5.0 (Linux; U; Android 6.0.1; SM-G900F Build/MMB29M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 OPR/21.0.2254.111757 Android 6 Galaxy S5
Mozilla/5.0 (Linux; U; Android 6.0.1; SM-G532G Build/MMB29T; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 OPR/21.0.2254.112007 Android 6 Galaxy J2 Prime
Mozilla/5.0 (Linux; U; Android 6.0.1; SM-G532F Build/MMB29T; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/56.0.2924.87 Mobile Safari/537.36 OPR/21.0.2254.112007 Android 6 Galaxy Grand Prime Plus
Mozilla/5.0 (Linux; U; Android 6.0.1; SM-A310F Build/MMB29K; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 OPR/21.0.2254.111920 Android 6 Galaxy A3 (2016)
Mozilla/5.0 (Linux; U; Android 6.0.1; LS-4508 Build/MMB29M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 OPR/21.0.2254.111921 Android 6 Flame 8
Mozilla/5.0 (Linux; U; Android 6.0.1; KIW-L21 Build/HONORKIW-L21; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 OPR/21.0.2254.111677 Android 6 Honor 5X
Mozilla/5.0 (Linux; U; Android 6.0.1; D5833 Build/23.5.A.0.575; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 OPR/21.0.2254.111920 Android 6 Xperia Z3 Compact
Mozilla/5.0 (Linux; U; Android 6.0.1; ASUS_Z010DD Build/MMB29P; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 OPR/21.0.2254.111920 Android 6 ZenFone Max