After buying numerous different coccyx cushions (see Coccyx cushions) I decided to take a chance and order the Triple-CV cushion from the U.K. manufacturers as they are the only distributors. After two months of daily use I can highly recommend this cushion. It has special cut-out sections in both the seat and backrest section. The seat has a firm foam with a layer of soft visco memory foam on top while the backrest has soft foam. It is by far the comfiest of the six coccyx cushions I have bought since being injured some years ago and is the only one that comes with a special backrest. The two sections fold neatly together and can be carried by the very handy stitched handles or shoulder strap. It flips open easily. I use it at home, in cars and at places like cafes and cinemas. These days I don't go anywhere without it and am amazed at the difference it makes to my level of comfort.
It was well worth the purchase price and the overseas postage costs were very reasonable. The staff at C.S. Ergonomics have been very helpful via email contact. They can be contacted at www.backcare-ergonomics.com and orders can be placed online.