said push buttons including respective carriages fixed thereon for {TAIL ~ sliding movement} therewith and having respective soft resilient compressible rubber like valve members fixedly mounted on the respective carriages for sliding movement therewith and facing transversely relative to {HEAD ~ the predetermined direction} of sliding movement, 
said push buttons including respective carriages fixed thereon for { TAIL ~ sliding movement } therewith and having respective soft resilient compressible rubber like valve members fixedly mounted on the respective carriages for sliding movement therewith and facing transversely relative to { HEAD ~ the predetermined direction } of sliding movement ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH