Used: Fair - Samsung S21 Ultra, various colours, 512GB £289.99 With Code + Free Next Day Delivery @ 4gadgets

Returns & warranty info‌ 4gadgets.co.uk/ret…rns
30-day FREE returns & 12 months warranty makes it very fair if anything goes wrong or if one finds overheating issues.
Also a 6-month warranty on the battery, probably within reason.