In further embodiments, {HEAD ~ a restrainer} can be provided to limit and control the movement of {TAIL ~ the spring arms} 
In further embodiments , { HEAD ~ a restrainer } can be provided to limit and control the movement of { TAIL ~ the spring arms }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL