During the second keynote address at Amazon’s re:MARS conference in Las Vegas, the company announced new robotics products heading to its hundreds of fulfillment centers around the world.

Brad Porter, head of robotics at Amazon, said the company’s been deploying a robotic palletizer for the better part of this year; it’s now lifted over two billion pounds of totes across Amazon’s hundreds of fulfillment centers. And in an effort to improve the speed and reliability of package sorting, Amazon has been rolling out a new sorting system — Pegasus — that’s driven two million miles to date and has already cut down mis-sorted goods by 50%, all while preserving the safety features of the existing drive system.

“In developing this, we realized we had an opportunity to rethink the way we designed robotic drives at Amazon,” said Porter. “Accuracy is super important. If you drop a package off the conveyor and lose half of it for a few hours, sort a package to the wrong destination, or drop it and damage the package, we can’t live up to our customer promise anymore. The results of this new system is that it just works better.”

Alongside Pegasus, Porter today introduced Xanthus, a highly compact, modular drive system that can be quickly adapted to new applications with accessories like Xanthus Sort Bot and Xanthus Tote. It’s a major redesign of Amazon’s primary robots, many of which it inherited from its 2012 acquisition of Kiva Systems.

Porter expects that, thanks to Amazon’s recent purchase of autonomous warehouse robotics startup Canvas and its associated technologies, both Xanthus and Pegasus will be able to move outside of predefined warehouse barriers to “interact collaboratively” with sales associates to do “a number of mobility tasks.”

“Customer expectations for convenience, selection, costs, and especially delivery speed and continue to increase, and we realize we need step function changes in robotics,” Porter said.

Both Xanthus and Pegasus join the 200,000 first- and third-party robots working alongside the 300,000 people at Amazon’s hundreds of sorting and distribution facilities. Earlier in the year, Amazon said that it’s already deployed north of 100,000 robotic systems in more than 25 fulfillment centers across the U.S.

“We are always testing and trialing new solutions and robotics that enhance the safety, quality, delivery speed and overall efficiency of our operations,” a spokesperson for Amazon said in a statement. “We believe that adding robotics and new technologies to our operations network will continue improve the associate and customer experience.”