Was in my local Co-op and noticed these.
I haven't seen this size bag around since I was a lad, they were huge 150g bags, almost Sensation size bags.
My local had Ready Salted, Cheese & Onion and Salt 'n' Vinegar.
The standard bags are 34.5g and they are 45p+ these days so these seemed like a real bargain to me.
Assumed they were on offer but couldn't find an end date.
Admittedly this won't make the nation any thinner, but if you've got the muchies and want a nosebag size bag of crisps..................
Sorry if it's been posted before I couldn't see it.
(Couldn't find a picture of it, not even on the Walkers website, if anyone else finds one then please add it)