I use the SRAM PG
"I use the SRAM PG 1170 cassette as an equal replacement for my stock Shimano Ultegra CS-R800 cassette. The SRAM cassette just feels ever so slightly better to me, and I use it with a SRAM PC-1170 Hollowpin chain."

Overall rating: 4.785714 / 5 from 14 reviews.
Review topics: ["quality","cassette","climbs"].
"I use the SRAM PG 1170 cassette as an equal replacement for my stock Shimano Ultegra CS-R800 cassette. The SRAM cassette just feels ever so slightly better to me, and I use it with a SRAM PC-1170 Hollowpin chain."
"the cassette was perfect for the order and the extra set of wheels. the quality matches existing cassette."
"Great quality with the 36 tooth cog!"
"Great Service."
"Love the 11-32 ratio for climbing; have used this model cassette in the past and had good luck. This one, however, seems to defy adjustment to make it quiet. Past ones have made chain noise in one middle cog, but this one also is noisy in the 32 tooth cog, giving you something to be annoyed at while climbing a long steep climb."
"Quality product purchased with quality customer service. Fast delivery."
"If you’re looking for a wider range cassette, this will do the trick. Just FYI, if you have a Sram Red Wifli medium cage derailleur, it does work with a 36T without a Wolf Tooth road link. However, it may depend on your hanger length. Great cassette for the money. You can’t go wrong."
"super nice items"
"Not much to say here. Good product, known SRAM quality."
"Light weight excellent and smooth shifting"