I use the 1.5 Theresa. I measured my other ones from Cookson and the 1mm was anything between .8 and .9 and the 1.2 were about 1.12, that’s useless really. They used to do a 3 strand which was quite nice but I see they’re selling .8 and 1mm to make your own so I suppose you could strand them up.
Curteis 18 in 1.5 arrived and they are good but their website is so difficult to understand. that I bought a foot of snake when I understood their wording that they were selling in 3 ft lengths:/ I have a useless ft of 3 mm snake now. I ordered more chain on the phone and I have no idea how much I spent , I wasn’t impressed really