Advice on boarding trolley case

When traveling, we will bring a suitable trolley case. We all know that there are many rules on flying. Large items can not be brought on board. What size travel trolley can be put on the plane?
1. In general, according to international flights, carry-on items, each passenger baggage shall not exceed 5 kg, the volume size of not more than 20X40X55CM, but first-class passengers, each person can carry 2 items, luggage items each The weight shall not exceed 5 kg, the size of the volume shall not exceed 20X40X55CM.
2. Unfortunately, more than the above size, weight or number of only checked. In addition, there is a slight difference between the provisions of each airline on the items to be carried with them. Therefore, passengers should consult with the consignment staff in detail when purchasing the tickets.
3. If your travel items are too many, can not bring the plane, it can only be checked, according to international flights, the weight of checked baggage each piece can not exceed 50 kilograms, the volume can not exceed 40X60X100 cm.
4. If more than the above provisions of the luggage, may need to pay another, and with the carrier's consent before shipment. Checked baggage in the luggage to ensure that the packaging is complete, the lock intact, binding a solid, can withstand some pressure, under normal operating conditions, safe handling and transport.