Campagnolo's Chorus 11 Chain has one big difference that separates it from the low weight of its more expensive Record and Super Record counterparts. With Chorus, the pins connecting the links are solid; with the more expense chains, the pins are hollow. This results in a weight difference of 0.34 grams per link. Other than that, the Chorus chain is the same as Campy's best offerings, with nickle-plated steel links, an anti-friction Ni-PTFE treatment, and a design meant to optimize the shaping of the cassette and chainring teeth for precise, smooth shifting.
Please note that, given the nature of the Chorus Chain's Ultra Link design, it requires the Campagnolo UT-CN300 chain tool for installation.