See also:

TWR (Tongue Weight Rating)
The TWR specifies the maximum permissible weight that the ball coupling of the trailer tow hitch can support. ...

Securing hooks
Only use the mounting hooks to secure items of luggage up to maximum of 9 lbs (4 kg) in weight. There are two securing hooks 1 on each side of the cargo compartment. ...

GTW (Gross Trailer Weight)
The GTW is the weight of a trailer including the weight of the load, luggage, accessories etc. on the trailer. ...