We designed this tool set to provide you with the basics that you'll need to make easy adjustments to your bike. The 15mm wrench allows you to easily remove and attach the front wheel of your PUBLIC bike. This is helpful if you have a small car or storage space. It will also tighten or loosen your pedals. Just for fun we put a bottle opener on the other end. The three way hex wrench, coated in rubber for comfort and grip, comes with the 3 most versatile hex heads (4mm, 5mm, and 6mm). The Y-Shape gives extra leverage which allows for easy adjustments to the height of your seat post and handle bar stem. It will also allow you to tighten up your rack.