Ujeeddo: Kookaha batroolka ee Graphite GPC waxa laga sameeyay kookaha batroolka oo tayo sare leh. Waa nooc ka mid ah walxaha kaarboonaynta oo tayo sare leh, oo leh kaarboon go'an, baaruud yar, dambas yar, heerka nuugista sare iyo faa'iidooyin kale. Waxaa loo isticmaali karaa in lagu soo saaro bir tayo sare leh, bir la shubay iyo dahaar.