To find the correct size, you should:
* Check your owner's manual: This is the most reliable source. The manual will specify the correct wiper blade sizes for your specific Silverado.
* Look at your current wipers: The size is usually printed on the wiper arm itself.
* Use an online tool: Many auto parts websites (like AutoZone, Advance Auto Parts, etc.) have tools where you can enter your year, make, and model to find the correct wiper blade sizes.
Without knowing the year and model of your Chevy Silverado, I cannot give you the correct wiper size.