The Polyair Red Series Load Assist Airbag Kits Are Specifically Designed To Suit Coil Sprung Vehicles.When You Load Up The Back Of The Vehicle Or Hook Up A Caravan Or Trailer, You'll Notice The Rear End Drop Down; This Drop Can Have Some Adverse Effects On Your Vehicle Safety And Handling.Symptoms Such As:- Suspension Bottoming Out- Rough Ride- Excessive Sway ; Body Roll- Unpredictable Braking Characteristics- Poor Headlight Aim All This Can Be Mitigated By Simply Installing A Set Of Polyair Red Series!The Airbag Kit Is Air Adjustable, Giving You Flexibility To Tailor The Level Of Support For Your Individual Load Types And Weights.Having A Correctly Sprung Vehicle For Constant Loads Is Always Recommended As The First Step, But In Most Cases The Coil Springs Are Rated Well Past What You Will Carry On A Daily Basis, Giving You A Rough, Uncomfortable Ride When Not Loaded Up.Having The Flexibility Of The Adjustable Polyair Red Series Means You Can Have A Smooth Oem Ride Comfort When Unloaded And Simply Adjust The Pressure When Towing Or Hauling. Simple.Features:- Air Adjustable From 5-35psi- Tough Moulded Polyurethane Construction- Easy To Install Using Common Tools- Easy To Follow, Illustrated Instructions- Quick Connecting, Easy To Use Air Fittings. 2 Year, Unlimited Km Warranty