1" thick soft foam is slightly contoured for a comfortable fit. Covered with stockinette and a Velcro® closure. Extra sleeve provided. Size width at chin x neck circumference.  Sizes are as follows:

Small 2 1/2 x 8" - 12"

Medium 3 x 11" - 15"

Large Standard 3 1/2 x 14" - 18"

Large Narrow 3 x 14" - 18"

Xlarge 4 x 17" - 21"