Mystery package

As I write, sitting in my warm, dry flat, the rain is pitter-pattering on the window. It's a sound I rather like. When I was a child, I would go into the box room, just to hear the rain bouncing off the skylight, while feeling all snug and warm. Well, I'm not going out there today.
    The package arrived yesterday. I told the delivery man what it was. You will have to guess what it is. Your answers should start "Has it got something to do with...."  I may, or may not open it today. (How to open it will be a test in itself.) It doesn't matter to me. I know what's inside the box. I know it will keep.