The 'Rear Stock' Adjustable Bag Rider is designed to replace the existing HS50 rider using the existing bolts. It provides the same superior functionality as the other ABRs with increase load capabilities as a third linear bearing and dowel is included. A larger thumb wheel is utilized to provide more torque and finer vertical movements. Hardened dowels are used. The rear dowel has a c-clip on the top to prevent over travel beyond the 1.5. Currently the ABR is only offered with one bottom which is .850 wide on the bottom and 1 on the top. Weight 1 lb 13oz. The bags made for the ELR or SQR bottom will work best. Caliber restrictions: None Made from 6061-T6 alum and Black Anodized Class II Please note that this product will not fit other Rifles without modification. Non-Affiliation Disclaimer. We are not affiliated, associated, authorized, endorsed by, or in any way officially connected with the Steyr Arms brands .