Complete DIY Installation Set: Each component is designed for a straightforward installation process, making it ideal for quick DIY repairs and upgrades on your RV. Universally Compatible & Precise Fit: Engineered to fit most standard RV windows and roof vents, these knobs feature a 1/2-inch shaft and a 2-1/4-inch diameter. Check your existing hardware dimensions for proper fit. Quality Direct Replacement: Replace old or damaged knobs with these high-quality plastic alternatives. Designed to match original specifications for reliable performance and consistent appearance. Ergonomically Designed for Comfort: The knobs feature curved edges and a textured grip for ease of use and secure handling when operating window cranks or vent mechanisms. Durable Material for Lasting Use: Made from premium plastic, these knobs resist wear and tear in varied environmental conditions. Smooth, burr-free edges enhance safety and durability. Color: Black Material: Plastic Package Contents: 4 x knob 4 x screw 1 x screwdriver Note: Color may vary slightly due to screen settings. Measurements may vary by ±1–3 cm.