AR-10 Receiver Wiper Sets Bore Techs patent pending AR Receiver Wiper Sets are the industrys most innovative and effective cleaning tools specifically engineered for meticulous cleaning of the AR barrel extension and upper. Each wiper set includes a cross shaped Barrel Extension Wiper and the circular shaped Upper Receiver Wiper. The AR barrel extension and upper receiver are notorious for colleting brass shavings, powder residue, debris, oil/grease, and solvents. This accumulation of debris can cause operational malfunctions and increase wear on your bolt, bolt carrier, and receiver. In the past, these areas have been difficult to properly clean/dry. Not anymore! The cross shaped Barrel Extension Wiper eliminates clumsy dental rolls and ineffective felts that fall off, barely clean, and pack full of fouling rending them useless. With Bore Techs Barrel Extension Wiper, simply spike a patch over the wiper and observe how the flexible rubber fingers compress as they pass through the locking lugs and spring open once inside the barrel extension providing a thorough and complete cleaning. The same principle is utilized with the circular shaped Upper Receiver Wiper. Spike a patch over the wiper and watch how it perfectly conforms to the receiver walls for a thorough and complete cleaning every time. The AR Receiver Wiper Sets are available in both AR-15 and .308 AR sizes. Why settle for anything less than perfection? Choose the bestA| Choose Bore Tech. Description: 1 x Cross Shaped Barrel Extension Wiper 1 x Circular Shaped Upper Receiver Wiper Material: Molded, Solvent Resistant Rubber Core: Proof Positive Alloy Threads: Male 8/32