With a complete hook arm and hook connector, it can be easily installed without other tools. You can easily carry it because it is compact and lightweight. You can effortless enjoy each bicycle travel with your baby or pets if you have a bike trailer coupler. Excellent workmanship and material makes it used for a long time. Made of high quality steel and nylon material, it is durable. The length of the product is 20cm, the width is 5cm, and the thickness is 4cm. The hook adapter can be compatible with general bicycles and electric bicycles. Run on quick release or flat axle wheels. Item Name: Coupler Hitch Attachments Material: Steel,Nylon Color: Black Silver Color Features: Lightweight, Good Toughness, Stable Size Details: Size: 20cm x 5cm x 4cm/7.87" x 1.97" x 1.57" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Lanyard 1 x Coupler Hitch Attachment