Buffalo Blizzard Swimming Pool Above Ground Winter Cover Clips - 40 Pack Install 2 cover clips per top rail. Dimension: Each cover clip measures 6" inches long Listing is for 40 cover clips Protect your winter cover by installing 2 winter cover clips per top rail. The cover is designed to help keep the winter cover from flapping in the wind and potentially damaging the cover. Each cover clip measures 6" long. How do you know how many cover clips you need? Each top rail will need 2 cover clips.