Radiator With Cap?

[brainbug007]

I know I'm probly daft and being a newbie here but I'm thinking about buying a rad off kit spares as the polo one I had cracked while I was trying to bolt it back on and now pisses out water I like the kit spare ones as they're new and the mounts are metal (I think) instead of plastic like the polo ones and it's a proper hole that a bolt with washer & nut could be used on instead of the bolt going into the rad. But I noticed that they sell two different ones, one without a cap http://www.kitspares.co.uk/shop/item...=4746&catsub=0 that's remote filled and pressure capped? Does the remote part of this description refer to the expansion bottle? The also do this one http://www.kitspares.co.uk/shop/item...=5104&catsub=0 which they describe as high efficiency for not much more but it has a radiator cap and a hose of some sort coming off it? What is the cap & hose for??