Rail Mounted Adjustable Bag Rider (Patented) is designed to clamp to a lower picatinny rail. It provides the same superior functionality as the other ABRs. It ships with the LSP made 2 hole Rail Clamp and 10-32 bolts (torque to 18 inch pounds -5/32 allen wrench). The ABR has about .95 of travel with the short dowel and 1.48 for the long dowel. The ABRs are CNC machined from USA made 6061 Alum, Anodized Class II Black and weighs 12-14 oz. As more rifles or rear stocks are identified as a direct bolt on application the list will be updated. ELR bottom is .850 wide x .5 tall V bottom is .850 tall and fits a standard 2 Stitch bag A new 'Quick adjustment' thread option (Coarse thread) is available for PRS, Hunting - use requires Hardened Dowels. Direct Bolt on Applications and Dowel lengths: Daystate Delta Wolf (Short Dowels) Gunnar PCP - Air rifle - (Short Dowels) Ghost - Brocock Carbine - (Long Dowels) Tikka T3X TAC A1 (Short Dowels ) Christensen Modern Precision Rifle and Rimfire (Long Dowels-you must order the picatinny rail from Christensen Arms) RAPS FAB Defense Stock (Long Dowels) GRS WARG and Bifrost -Long Dowels (picatinny rail required) Savage AXIS 2 (Short Dowels) requires the lower rail section to be attached Magpul CTR - (Long dowels) 'AR Mounting bracket' Required CZ600 Range-Short Dowels Oryx chassis 'Howa' (Long Dowels) mount the M-lok pic rail available from the MDT site if a slot is on the bottom of your stock (If you don't have a slot the 'Flat Mount ABR' can be mounted if you drill and tap holes into the stock contact us first - I'll walk you thru it) CZ457 - 22LR - (Short Dowels) Howa TSP-X - (Short Dowels) -order the pic rail from the Australian company that makes the frame. Southern Cross Small Arms (SCSA) - (Short Dowels) - factory pic rail is required. Vertical grip is required. Huglu Ovis - B08 - Long Dowels Modifications required: FX - Impact and Maverick Ruger Precision Rifle Rimfire (Short dowel) Modifications Required Please note that this product does not fit the Ruger Precision Rimfire Rifle without modification. It does not fit the Ruger Precision Rifle or Magnum. Caliber restrictions: .338 and smaller calibers can use the Standard dowels .33XC and larger needs the Hardened dowels (Black Oxide Finish) PRS needs Hardened Dowels (Black Oxide Finish) FAQ's: Which MODEL do I choose? Rail Mounted (RM) ABR top section is the same for all. Only the dowel & stud lengths are different. Which DOWELS do I choose? .338 and smaller calibers will use the Standard Dowels .33XC and larger needs the Hardened Dowels PRS needs Hardened Dowels.