2 pieces: Fire damage.
4 pieces: CRIT Rate against Burning targets.
Read the linked source for exact values and activation text.
DRIVE DISCS / PATCH 3.2
Inferno Metal
Fire equipment set.
Fire
RECORD IDINFERNO-METALFACT CHECKED
Fire equipment set.
2 pieces: Fire damage.
4 pieces: CRIT Rate against Burning targets.
Read the linked source for exact values and activation text.