A cycling valve , reversing valve and {TAIL ~ actuator mechanism} provide operator control of {HEAD ~ the devices} contained in housing  
A cycling valve , reversing valve and { TAIL ~ actuator mechanism } provide operator control of { HEAD ~ the devices } contained in housing
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH