Baggage Service - VietJet Air

What the official page says

Each passenger may carry one main cabin bag (56 x 36 x 23 cm) and one small item (30 x 20 x 10 cm, or a 40 x 30 x 10 cm laptop bag, or a 114 x 60 x 11 cm garment bag), with a total weight of 7 kg. A cabin baggage tag obtained at check-in is required.