I was able to do some research and the Business variant is currently no longer on sale. Unfortunately, I can't say at the moment when and if it will be on sale again. Below is the link to the business version, whereby the product can be added to the watch list and if an offer should be active, a notification will follow. According to the scope of delivery, both are equipped with the same receiver and have the same specifications. At Logitech, "for business" generally refers to the software, which differs from that of private users, the warranty services or packaging and price.
Logitech Mx Master 4 For Business (Wireless)