Ian - firstname.lastname@example.org
My old (third in ten years) Triple-C coccyx cushion was past its best so I just bought a new one. What a difference! This cushion folds and carries just like a briefcase and can be used, single, double or triple thickness. I prefer triple for the car, and double for dining etc. At £42 (inc. VAT) they are not cheap. Butt it's money well spent.
The cushions were originally obtainable from the Comfort Shop, which is now C.S.Ergonomics (see backcare-ergonomics.com) based in Addingham near Ilkley, West Yorkshire.