R1 Concepts 623-03039L RNC Series Drilled Brake Rotor

The R1 Concepts 623-03039L RNC Series Drilled Brake Rotor is a precision-engineered replacement rotor designed for improved braking performance and thermal management. Featuring a drilled pattern, this rotor promotes heat dissipation and helps evacuate gas, dust, and moisture from the rotor surface for consistent, fade-resistant stopping power.

R1 Concepts manufactures this rotor from high-grade G3000 metallurgy cast iron, ensuring dimensional accuracy and long service life. Each rotor is computer-balanced and finished with a corrosion-resistant coating on the non-contact surfaces to prevent rust during storage and off-vehicle periods.

Key Features:

• Drilled rotor design for improved heat dissipation and reduced brake fade
• High-grade G3000 cast iron construction for durability and consistent performance
• Computer-balanced for smooth, vibration-free braking
• Corrosion-resistant coating on hat and non-swept surfaces
• Direct OE replacement — no modifications required for installation
• Meets or exceeds OEM specifications for thickness, hardness, and runout

The R1 Concepts 623-03039L is a direct-fit, OEM-style replacement rotor suited for daily driving and performance street use. It is a left-side (driver side) rotor as indicated by the "L" suffix in the part number.