B-screw tension plate cracked completely (I believe on the first climb) and later bent/twisted on the descent. Horrible design. Don't buy this product, or at least not the mx version. Buy the top-end ms, or an mz. Actually, just spend the extra 30$ and get a gx derraileur. If you're planning to use this with a hyper-high range 10 of 11 speed cassette, I seriously don't recommend it. Wasn't given a refund, sunrace customer service sucks. "David" from Napa, CA sunrace corporate, told me he'll ship it np, will be expedited from Taiwan. Two days later tells me the entire factory is on vacation for a Taiwanese holiday.