6711A Single-head chestpiece for adult
6711X Single-head chestpiece for child
6711C Colored Single-head chestpiece for adult
6711N Single-head chestpiece for adult,Non-chill rim
6712A Dual-head chestpiece for adult
6712X Dual-head chestpiece for child
6712C Colored Dual-head chestpiece for adult
6712N Dual-head chestpiece for adult, Non-chill ring