I can't find exact details between a sinularia vs nepthea, and it appears to be a reclassification, making the name interchangable in the hobby.
 
Either way, been calling it a neon green nepthea. These are very well started colonies grown on coral disk. An instant show piece in tanks up to 40 gallons, but will grow into an impressive dispaly in larger tanks.
 
Medium to high light to maintain the intense green. Does best in alternating flow patterns, but highly adaptable in any flow conditions. Great beginner coral, as well as a must have for any soft coral tank.