{HEAD ~ The system} effectively seals {TAIL ~ the active agent chamber} and isolates it from the environment of use 
effectively seals
{ HEAD ~ The system } effectively seals { TAIL ~ the active agent chamber } and isolates it from the environment of use
HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH