Both products (somnipax shield and somnipax CPAP pro) are identical in terms of design and material. They merely differ in their respective application purposes and instruction manuals. somnipax shield helps to prevent open-mouth snoring. somnipax CPAP Pro is intended to be used with a CPAP nasal mask and is meant to prevent leakage. The instruction manuals have been configured accordingly. The costs of both products is, however, the same.