The KG804 Rixen & Kaul Retrofit Coupling Set is an accessory for the Rixen & Kaul bike rack system. It is designed to retrofit an existing bike rack to be compatible with the Rixen & Kaul accessories, such as baskets, bags, and panniers. The set includes two coupling components that are designed to be mounted onto the bike rack. The couplings are made of durable materials and are compatible with a wide range of bike racks. The KG804 Rixen & Kaul Retrofit Coupling Set is easy to install and requires no special tools. Once installed, it allows for quick and easy attachment and detachment of Rixen & Kaul accessories, making it a versatile solution for cyclists who frequently carry cargo on their bikes.