TR438 Rubber Valve Stem made for Spare Tires. OEM Mercedes-Benz 0004002913 (spare tire). Fits most Mercedes-Benz spare tires. Product size: 45 x 15mm/1.77 x 0.59" Effective Length: 1 1/4" Valve Hole: .350; Installation steps: 1. Remove the valve core to deflate the tire; 2. Separate the toe of the tire and remove it from the rim; 3. Remove the valve and clean the holes and dirt on the rim;4. Install a new valve from the inside of the rim, it will snap into place; recommend using vaseline for easy installation; 5. Install the tire correctly and inflate to the rated air pressure; 6. Replace the valve cap with a new one.