Probably the cheapest service part I've put down on my Jeep XJ. How many swear words I wouldn't have thought of if I'd bought them sooner. The exchange takes 10 minutes. They will be inserted immediately. DO NOT REMOVE THE METAL CLAMP! They came with no instructions so removing the clip from the first seemed like common sense. NOT CORRECT! Break off the old ones and just put in the new ones. Remove and replace just one side!