O.E.M. Parts are parts made by the original equipment manufacturer, in other words you car maker makes the best parts for your car in terms of fit, strength, and corrosion protection.

Aftermarket parts also know as "QRP" "Non O.E.M." or other subtle names your insurer puts in your policy and on estimates. These parts are make by companies other than your vehicles manufacturer. Usually in Taiwan, China, of inferior steel, strength, and mist notably fit.

Tell your insurance company you want to protect the value of your vehicle and you will only accept O.E.M. Parts