Check the listing for details. AMAZING Delta Series Bore Guide from Wheeler # 156777. Condition: New. Listed at 36.24 USD. WHEELERBore Guide#156777The Delta Series Bore Guide will help protect the bore and action of your RFL by properly aligning the cleaning rod and reducing solvent overflow. Cleaning without a bore guide can allow the rod to "bow" and rub or gouge chamber and throat of the bore causing real damage and loss of accuracy. Keeping the rod properly aligned not only protects yourbarrel, it directs the force exerted on the cleaning rod handle allowing tight patches to be pushed more easily.The Bore Guide is precision CNC machined aluminum with a durable anodized finish. It fits securely in any 556 / 223 upper and can be retained in place by closing the dust cover on the upper which engages a groove in the guide. The bore guide also has chemical resistant O-rings for retention in uppers without dust covers. A solvent port is conveniently located to the rear of the guide which extends out of the upper making it easily accessible during cleaning.SPECS:Protects chamber & Bore from damageEnsures proper rod alignment for easier cleaningReduces solvent leakage into the actionAnodized aluminum for durabilityIntegrated solvent port10 / L R Bore Guide fits .308Secures in place with dust cover engagement