safety systems comprised of wireless sensors for detecting obstacles in railway grade crossings; wireless transmitters and receivers for communicating the detection of obstacles in railway grade crossings; wireless sensors for detecting obstacles in railway grade crossings; transmitters and receivers for communicating the detection of obstacles in railway grade crossings; sensor devices for detecting obstacles in railway grade crossings; devices for wireless radio transmission and reception; ...

Chemical preparations, namely, degreasing and cleaning solvents; Degreasing agents