Anti-Roll bars are fitted to most later cars as standard, these tie the lower suspension components together across (usually) the front and rear of the vehicle. These are fitted to aid the vehicle against understeer of oversteer. Ultra Racing sway bars are designed to be slightly larger in diameter than their OEM counterparts in which further stiffens the lower suspension parts to create a safer, more responsive drive. Keeping the car from leaning (swaying) during cornering is paramount when keeping the vehicle consistent and predictable during fast road conditions. This is done by distributing the force and energy throughout both the nearside and offside of the vehicle during cornering to keep the vehicle level across all four wheels instead of letting it lean to one side. These work extremely well when coupled up with upper strut bars as the front and rear suspension systems will work as one unit rather than fully independent. We advise that these are only used for road or track use as for off-roading they can have an adverse effect when making the vehicles chassis too stiff.