Mounting Post - Transitional in Chrome

Hello mbrooking, Thank you for your question about the Delta Faucet RP64150 Mounting Post - Transitional. I apologize for any difficulty finding this information. We are happy to help! Unfortunately, we do not have a measurement for the diameter of this part. For information about installing a slide bar model that uses this mounting post, please see here: https://media.deltafaucet.com/MandI/86512%20Rev%20F.pdf Please reach out directly at customerservice@deltafaucet.com or 1-800-345-DELTA if you have any questions or need additional assistance. Thank you for being a loyal Delta Faucet customer. Best regards, Bryan