The racers39 choice 105 brake callipers come in a compact and lightweight design for high performance dual pivot calliper brake with super slr ev design for quick linear response increased rigidity and improved braking power must be used in conjunction with st 5800 st 6800 or st 9000 stis for correct leverage ratio enhanced brake arch proportions give a quicker linear response and increased power low profile outer cable stop position improves cable routing for reduced friction