Rasmussen's Mixed FireBall Sets sets are a contemporary replacement to old and outdated traditional logs sets. Fireball set are sold in widths ranging from 18" to 48" wide, so your sure to find a kits that meets your needs. Each kits come in 6 colors ranging from Black to Light Gray. Depending on the size and shape of your fireplace burner these kits can be used in both single or double face fireplaces. Mixed Fireballs should be used with Rasmussen CS Burner or CXF Burner. Set Size No. Pieces Recommended Burner 18 18 CS18, CXF18 20 20 CS21, CXF21 24 14 CS24, CXF24 30 29 CS30, CXF30 36 46 CS36, CXF36 42 52 CS42, CXF42 48 59 CS48, CXF48 Note: Fireballs warranties are void if Fireballs are used without a Rasmussen recommended burner. The appearance of the Fireball's will change over time due to the scooting or carbon build up that is inherent when burning all gas types.