Check the listing for details. Estwing R-1 Butterfly Pattern Replacement Blades. Condition: New. Listed at 13.48 USD. Estwing R-1 Butterfly Pattern Replacement Blades Manufacturer:Estwing Part Number:R-1 Heavy-duty replacement blades for Roofing Knife. Replacement blades for Roofing Knife Heavy Duty 2.5-inch length Roofing accessory Made in the U.S.A. About the Manufacturer Since 1923, Estwing Tools has chiseled out a solid reputation as an American brand recognized for their quality workmanship. Known for their innovative designs and superior craftsmanship, Estwing Tools offers a large variety of tough hammers, axes, pry bars, and specialty tools that cater to tough jobs. With a top-notch brand like Estwing, you can bet they?ll help you get the job done! Bulk Pricing For customers who wish to order large quantities of this item and would like to receive bulk pricing, please contact us directly and we will provide the best price possible.