Cokin filters for lens

Been looking through B&H for a variety of Cokin filters for my lenses but there is not much information about them.

It looks like the P series is the best to get as its 85mm x 85mm but will need the P series holder plus the adapter ring or as the just the holder only & the filter slides into it?

You need both the filter holder and the adaptor rings. Otherwise how will the holder going to attach to the lens? The system basically has three components: filter, holder and adaptor.

In all honesty, I don't use much of the holder or adaptor rings anymore. I tend to hold the filter at the front of my camera.. too much of a fuss to take this off and put that on etc. all the time.

I only use Cokin ND grads.

lot of good info in here https://photography-on-the.net/forum/showthre​ad.php?t=315987