The Summit Ascent features the R2S Solid cover wrapped around the Centripetal HD A.I. Core. I drilled mine 5 x 3, which is the say layout I have on my trusty Optimum Idol. After throwing this ball for awhile, it will be getting a lot of use because it is similar to the Optimum Idol but just the next step down in my bag so when the Idol is too much itll be time for the Summit Ascent. It is a also a good mixture of both the original Summit and Summit Peak and definitely fits in-between them even though it is a solid but because of the R2S it makes it a lot cleaner. I highly recommend the Summit Ascent for bowlers of all skill level.