The Genuine BMW Brake Caliper Guide Pin Boot Kit (part number 34116768189) is a set of rubber boots designed to fit onto the guide pins of your BMW's brake calipers. These boots help to protect the guide pins from dirt, debris, and moisture, which can cause corrosion and affect the performance of your brakes. This kit includes four boots, enough for both front and rear brake calipers. It is a genuine OEM (original equipment manufacturer) product, ensuring a perfect fit and high quality. Regularly replacing these boots can help maintain the longevity and effectiveness of your BMW's braking system.