Outdoor Stick Up Cam Plug-In - Must use extra cable?

Hi, I'm installing a stick up cam plug-in under the eaves outdoors and plugging it into a socket in my attic. I don't need the extra length of cable provided by the additional cable however I notice that the plug on the extra cable includes a 3A fuse whereas the 'plug' adaptor for the transformer when not using the extra cable does not appear to have a fuse. The manual (both paper and website) does not explicitly state the extra cable is required for outdoor installation implying it is only required for the extra length. Does anyone know whether the use of the extra cable is required/recommended for an outdoor installation? Thanks for your help, Andrew