This protects both the chamber and the bore from abrasion by the cleaning rod during regular cleaning. "Universal" means that this set will fit most bolt actions and AR's. even Includes adapter sleeve for AR-15's and interchangeable tips that fit .17 to .416 caliber rifles.
Specifications:

Type	Bore Guide
Size	.17 Cal to .416 Cal
Quantity	1 Set
Bristle Type	None
Length
Includes	Adapter Sleeve for AR-15's
Material	Aluminum
Tip Feature	N/A
Battery
Thread Pattern	N/A
Protects	Against Carbon Build Up
Suitable For	Rifles
Eco-Friendly