These are a CNC molded 10” wheel side mount adapter for rear 10" Max mounting depth will vary by bag manufacture. Max OD is 10.2 With a 9" cutout. you may need to open the mounting to accommodate different size baskets.
Fitment will also vary by bag manufacture. Using a Quality bag or stock bag will achieve the best results. The inside diameter may have to be opened slightly as there are different speaker manufactures on the market. All new designs beginning 12/1/21 and material come with Speaker and ring mounting hardware. Threaded Inserts for speakers ( 8 ) 10-24 Stainless steel hardware, 16 outer ring hardware. Drill bit and tool to put in inserts. Panel bond not included.
It is recommended but not necessary to use a 2 part epoxy to bond the adapter to the saddle bag. A good example would be 3M 08115. You should also have some knowledge of body work as you will be cutting the saddle bag.
**due to many variations of saddle bags these were CNC using stock bags. Depending on the bag slight modifications may have to be done to the adapter. I.E sanding to the mounting face of the adapter or use of silicon caulk to fill in small gaps. Using a quality aftermarket or stock bag will achieve the easiest and best results.