The Angle Mounted Adjustable Bag Rider (Patented) is designed to bolt directly to the bottom of the MDT stocks (and some Savage) with supplied bolts. There must be a mounting SLOT in the bottom. Two lower rider options are available - the V and ELR. The ELR base is .850 wide. The ABR provides rock solid stability, straight tracking and vertical adjustment. The ABRs are CNC machined from USA made 6061 Alum, Anodized Class II Black and weighs 12-14 oz. There are four mounting holes providing the options to cover stock variations - select the two mounting holes farthest from each other. A 5/32 hex wrench will be needed. The ABR provides about .95 of travel for the short dowel and 1.48 for the long dowel. Older models stocks 'without the slot' will need machining to mount the 1/4 bolts. A new 'Quick adjustment' thread option (Coarse thread) is available for PRS, Hunting - use requires Hardened Dowels If you do not see your rear stock listed below there are Two pics that show the measurements needed to verify if the stock will accept the long dowels. DOES NOT FIT THE NEW ACC ELITE with lower support bar that attaches to the grip (even if you remove the bar) Bolt On application and Dowel Length: ACC - Non-folding -Long Dowels ACC - Folding stock- Short Dowels ESS - Non-folding - Long - Dowels ESS - Folding stock - Short Dowels SRS - Skeleton Rifle Stock - Short Dowels LSS-XL - Short Dowels SRS-XF - Short Dowels SCS-Lite - Long Dowels (The shorter tube length may require the Folding Stock Adapter to increase LOP- or a longer tube) SCS - Long Dowels (The shorter tube length may require the Folding Stock Adapter to increase LOP- or a longer tube) Savage Impulse Elite Precision - Long Dowels Colt CBX - Long Dowels Faxon FX7 - Short Dowels HTI Milano - using MDT rear stock Modification Required: Savage B22 & B17 - Long Dowels - Minor modifications are necessary as M-lok nuts and bolts will be required and the counter sinking of the heads on the bottom of the ABR will be required for a flush mount. Caliber Restrictions: .338 and smaller calibers will use the Standard Dowels .33XC and larger need the Hardened Dowels PRS use requires Hardened Dowels FAQs: Which Option do I choose? Angle Mounted ABR top section is the same for all. Only the dowel & stud lengths are different. Which lower rider (ELR or V) do I choose? The ELR is .85 wide and .5 tall the V bottom fits a 2 stitch bag. Which DOWEL Material do I choose? .338 and smaller calibers will use the Standard Dowels .33XC and larger needs the Hardened Dowels PRS requires the Hardened dowels Which Thumb Wheel thread do I choose? Fine Thread (standard) - bench rest, ELR, Fclass, Coarse Thread - PRS and timed events when faster movement is needed Which Adjustable Grip is suggested? The Vertical Adjustable Grip provides the maximum spacing behind the grip. Rear weight will need to be modified to clear the bolt heads - a dremel can be used Please note that this product does not fit anything other than the MDT / Savage with a MOUNTING SLOT. Non-Affiliation Disclaimer. We are not affiliated, associated, authorized, endorsed by, or in any way officially connected with the Modular Driven Technologies or Savage brands .