HPS Performance Products HPS 4-1/8" (105mm) Silicone Straight Coupler Hose, High Temperature 4-ply Reinforced Length:4" Can I order just one

Can I order just one cover or do I have to buy two

or will my factory hardware work

Hard panel construction with sealed optics designed for street and trail use

Apexi- N1 EVO Muffler - Piping Diameter (mm): 60mm

Do I need to flush the AC system before installing this

HPS Performance Products HPS 4-1/8" (105mm) Silicone Straight Coupler Hose, High Temperature 4-ply Reinforced Length:4" Can I order just oneHPS 4 1 8" (105mm) high temperature 4 ply Reinforced Silicone Tube Coupler Hose meet and exceed SAEJ20 industry standards, ideal for heavy duty pressure connections and provides excellent resistance for high temperature applications. HPS performance silicone Tube Coupler Hose is designed and engineered to meet high performance requirements specified in various industry standards, therefore make it great for automotive, diesel trucking, industrial,