A camera mountable arm includes a first segment, {HEAD ~ a second segment}, and {TAIL ~ a third segment} 
A camera mountable arm includes a first segment , { HEAD ~ a second segment } , and { TAIL ~ a third segment }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL