The HJC RPHA 31 Dereen MC21 is a small open-face motorcycle helmet designed for riders who want advanced protection, quiet performance, and everyday comfort. Its Premium Integrated Matrix (PIM) Evo shell combines Carbon-Aramid Hybrid and Natural Fiber reinforcement materials to enhance shock resistance while maintaining a comfortable, lightweight design. The elongated shell and extended chin EPS provide an encompassing full face-level fit, while the aerodynamic shape helps reduce air resistance and improve stability at higher speeds.
Built for controlled airflow and reduced riding fatigue, the RPHA 31 uses two intake vents and four exhaust vents to support front-to-back ventilation. Wind tunnel-tested development helps minimize turbulence and noise, while the shield holder reduces drag and keeps the visor securely in place. The included Pinlock® 120XLT® DKS467-ready HJ-39 shield provides 99% UV protection and features an anti-scratch coating for dependable visibility. An integrated smoke-tinted sun visor with anti-fog treatment deploys through the bottom-positioned operating system and offers multi-step adjustment, including positioning up to 10 mm closer to the face for personalized shading.
Inside, the RPHA Premium Fit interior uses advanced antibacterial fabric with moisture-wicking and quick-drying properties. Removable and washable crown and cheek pads simplify maintenance, while 3D-contoured cheek pads and interchangeable sizing options help riders achieve a precise fit. Reflective material adds visibility in low-light conditions. The helmet accommodates second-generation SMART HJC Bluetooth communication systems, sold separately, allowing riders to add integrated communication without distracting from the road. This HJC helmet is supplied in Small and is identified by manufacturer and vendor part number JA19NUS4221V.
Features:
- Size: Small
- Model: RPHA 31 Dereen MC21
- Brand: HJC
- Manufacturer Part Number: JA19NUS4221V
- Vendor Part Number: JA19NUS4221V
- Shell: Premium Integrated Matrix (PIM) Evo construction with Carbon-Aramid Hybrid and Natural Fiber reinforcement
- Protection: Multi-density EPS and extended chin EPS support shock-resistant performance and a full face-level fit
- Shield: Pinlock® 120XLT® DKS467-ready HJ-39 shield with 99% UV protection and anti-scratch coating
- Sun Visor: Integrated smoke-tinted, anti-fog visor with multi-step adjustment
- Ventilation: Two intake vents and four exhaust vents provide front-to-back airflow
- Interior: Removable, washable, antibacterial, moisture-wicking, quick-drying crown and cheek pads
- Fit: 3D-contoured cheek pads and interchangeable pad options support personalized comfort
- Communication: Compatible with second-generation SMART HJC Bluetooth communication systems, sold separately
- Visibility: Reflective material improves visibility in low-light riding conditions
- Fitment: Designed for motorcycle and powersports riders seeking an aerodynamic open-face helmet with integrated sun protection