Direct replacement seals for your Formula bleed ports and bleed screws. 100% Compatible with DOT brake fluid. Our replacement Formula O-ring seals enable you to renew your bleed port seals on your Formula brake set during the bleed process. Formula recommend that you visually inspect the o-ring seals around the calliper and master cylinder bleed ports to check their condition, and if needed they should be replaced with new. Therefore it is a good idea to have some to hand when you attempt the bleed process to ensure that you are able to finish the job! Note: Please select your brake model from the options above to ensure that you receive the correct size. We supply these o-rings in sets of 5. Note: Image is for illustrative purposes only. Depending on your chosen brake model the o-rings included may vary in size or contain multiple sized o-rings to suit your brake.