It uses Japanese WALBRO Carburetor, Italian ignition coil and NGK Spark Plug etc. NS872 Power Head clones stihl MS 381 which has decompression valve.
It doesn't upgrade any parts. The Power head and bar combo are two separate parcels. So you will receive two parcels in total.
There are slight color difference between the picture and the real item caused by light brightness, hope you can understand.