The 28 year old defender, whose father Mel played for the Greens during the 1994/95 season, arrives at the Lane from Peterborough Northern Star.
Prior to joining Peterborough earlier in the season, Mattless had been playing for March Town United, where he was club captain.
With today's game at Halesowen Town being postponed, Max could make his debut at home to Bedworth United next weekend