The mouth piece expansion is primarily in girth and the bulb pump has a metal quick release valve.
The mouth piece's semi-rigid rubber bulb/plug is of a comfortable density allowing for extended wear.
It would be great combined with a hood or on its own.

Color: Black
Thickness: .04 inch (1 mm)

Measurements in its initial state (un-inflated):
Mouth piece length: 2 ½ inches (6.4 cm)
Mouth piece girth: 5 inches (12.7 cm)