Details: Performance Resin: Model: P-Q12RS Blue color backing Increased heat stability Shorter bed-in process Provides a light lever feel Increases power transfer with a snappy initial bite Semi-Metallic: Model: Q20.11 Semi-metallic organic compound Red color backing Minimal noise in all conditions Sintered Metallic: Model: P-Q15TS Sintered full metallic compound Copper color backing Increased heat stability Increases consistency in all conditions and for heavier bikes and riders Compatibility: Compatible with all TRP 4-piston calipers