Talley 1 piece ring/base?

Ok guys/gals I'm new to this site and I'm sure this has been asked numerous times. I just bought a Predator Max 1 in 260 and I will be mounting a Bushnell Elite 4200 4-16x 40mm with adjustable objective. The scope is a few years old and has the objective adjustment on the bell not the newer side focus style. I have decided to go with the Talley 1 piece ring/base in medium height(?). After emailing Talley I'm more confused than ever. Talley stated I would need the model #94X725, which are the 1 piece medium "extended". After doing a cross reference I noticed the 1 piece medium, for round receiver accutrigger, Talley #940725 and 94X725 "extended". Does anyone know what the difference is with "extended compared to the "non-extended". Thanks for any help. :confused:

I would think it would be the front portion extends out over the barrel nut.

The 940725 non extended are similar to standard rings & bases that position the ring center between the base screws. 94X725 extended rings are made with the ring offset from the center, can be mounted with ring towards front or towards rear of receiver, allowing more adjustment of scope position.
There are pictures of offset rings on the brownells web site, click on Optics & look under mount sets. Also can look on Talley site, they have a dealers list, might be one near you.