Yes. So 2.0 in the knee was after putting it down the controlled launch, getting a lot of feedback, we made a number of improvements on software and hardware that we're making it kind of easier to use in many ways, but also making it really very seamless with our EMPOWR instrument sets as well. And so the 2.0 was then kind of more of a full launch of ARVIS, but we definitely decided to do it in a step-by-step way just to make sure that given that it's brand new to the world of technology, let's get 15, 20 docs using it, get some good feedback, help them to ramp up, and then use what we learn there to make sure that as we go to a broader set of doctors, one, we've got a great value proposition in terms of being able to help them understand how it's going to be valuable, but also we've got the ability to help them to ramp up fast and effectively with it.
And so that's what the 2.0 launch was, and we're right on track with that in terms of, as I said, a couple of dozen surgeons using ARVIS, some using it very heavily some less heavily. The ones that are using less heavily, we're learning why and how do we ramp them up in terms of how heavily they use it, and there's some good learnings there, both about how to ramp surgeons fast, but also about which surgeons to target more as we do the broader launch. And then we've now got plenty of inventory on hand ready to do a broader rollout as we work through this year, a lot of excitement in the field around the ability to bring ARVIS to a broader set of hip and knee surgeons, but particularly for the knee at this point as we work through this year.
So we would expect that number to expand and be a good facilitator to our knee conversion efforts. But also start to generate a small but growing and high profit recurring revenue stream on the knee front. On the shoulder front, as I said, it's just an initial launch. Think of shoulder in the second half of this year being kind of where our knee was a year or so ago in terms of getting that first launch into the marketplace in the second half of this year and getting some good feedback that allows us to keep revenue and improving the product. We've been focused on making sure that by 2025, we are right there in the market with a very strong shoulder ARVIS offering to continue to be a strong leader there in shoulder with technology, as we always have been. And we're right on track for that with this announcement about the shoulder clearance for ARVIS that just recently happened.