The second is a window related to arbitration, and it carries some extra restrictions. For this window to open, the team has to have a player that filed for arbitration. This window opens on the third day after the team's last arbitration is concluded (or settled, if it doesn't make it to a hearing) and is open for 48 hours. There are also restrictions on which players can be bought out - First, the player has to have been on the reserve list as of the last trade deadline (so no buying out that off-season signing you regret until the next trade deadline). Second, there is a minimum cap value for a contract to be eligible for this - $2.75m AAV initially, but the value goes up based on the average league salary each year. The notable absence in those restrictions is that it has nothing to do with who went to arbitration, any player who meets those two restrictions can be bought out. There's one last catch, though - this can only be done three times by each team. Not three times per year - three times over the entire length of the current CBA.