Masta stablemasta 400 fixed neck the stablemasta 400 fixed neck is an essential to any horse owner who wants to keep their horse comfortable when being stabled the dual channel quilting has a 400gm thermal filling to the upper section compared to a 300gm thermal filling included to the lower section for extra warmth 1000 denier polyester fabric has also been added to the upper section of the rug whilst the lower section features a 600 denier outer which is also waterproof and breathable