Check the listing for details. Extend-A-Post Barbwire Extension - For 1-3/8" Toprail - 6 Pack. Condition: New. Listed at 65.95 USD. This listing is for a pack of 6. This is one of our top sellers because of all the different uses and how quick this item can be added to your existing fence. Great buy! These fast and easy barbed wire (barbwire) arm extensions were designed and are manufactured onsite at our facility in eastern North Carolina. The design was developed and implemented by our head engineer who brings to the table more than 42 years of experience in the industry. These extensions are installed on existing fence, eliminating the need to remove and reinstall the top rail. Extensions are simply bolted onto existing top rail - fast and easy. Bolts are included. Extensions can be positioned at any angle from vertical to 90 degrees. Price is for 6 extensions with bolts.