{HEAD ~ This illumination system} is usually based on {TAIL ~ electroluminescent , incandescent or LED devices}, which require special controls, power supplies, dimmers and so on 
is usually based on
{ HEAD ~ This illumination system } is usually based on { TAIL ~ electroluminescent , incandescent or LED devices } , which require special controls , power supplies , dimmers and so on
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH