SECURE FRONT END SUPPORT - Drive With Confidence Knowing Your Bike is Secure. High Vehicle Stop Force Protection is a Unique Car Bike Rack feature to Secure and Brace the Entire Bicycle. DUAL LOCK SYSTEM - Security is High Priority and is Not Taken Lightly. Dual Key with Dual Locks Provide Extended security. Lock Arm Secures Your Bike & Secure Rack to Vehicle Cross Rail. REAR TIRE BRACE - DUAL Brace Added to Secure Rear Wheel. This Vertical Bike Rack system has a Rear Tire Metal Support Bar & Heavy Duty Plastic Adjustable Strap to Lock to Fasten Rear tire to Base. VEHICLE DOOR STEP - Free Heavy Duty adjustable Door step is Included with Purchase. This Tool Assists with Loading and Mounting all Bicycle sizes to the Heavy Duty Bike Rack. LOW PROFILE Design - Sleek Design for Low Wind Resistance. Added Folding Technology Reduces Much of the Overall Length of this Bicycle Roof Rack While in Stow Mode. Only 4" Side Profile Exposure. Car Roof Bike Rack with added Foot Step for easy access to Car Roof