Efficiency is everything, and RETRAC aerodynamic mirrors are built to help maintain this efficiency on heavy-duty trucks. Their smooth, curved construction allows them to cause less wind resistance and drag, while featuring an original equipment style to maintain an OE look on the truck. They're the perfect OE west coast replacement for a wide variety of heavy-duty truck applications.This replacement glass set is designed to fit 8" x 19" dual-vision aerodynamic mirrors with a heating element. It includes both the flat glass and convex glass pieces. Both are constructed with first-surface, electro-chrome glass to eliminate glare and maximize safety.