What type of bag does this vacuum cleaner use?

It’s the Kenmore Progressive Upright Vacuum Cleaner with Inteli-Clean System (35922). I bought it at Sears a while ago, and now I need more bags for it. It is no longer on the Sears website, but it is on the K-mart website, and I know the companies are jointly owned. I can’t find where it says what type of bag to buy. I know I need to get a HEPA one, but I don’t know what letter (O, V, Y, etc.) Here is a link to it:

http://www.kmart.com/shc/s/p_10151_10104_9990000057225311P?keyword=kenmore+progressive+upright+vacuum+cleaner&prdNo=1&blockNo=1&blockType=G1

Thanks!