I believe that means you will need a large mount (14mm) bar. Most likely a 3002 mount per Stihl's designations. You won't be able to run anything that's a small mount (12mm) which would be found on almost anything smaller than your saw (066, 064, 056, 044, etc.).
The 3001 and 3002 are both large mount, but the tensioner and oil holes are in different locations. You will either need a 3002, or a 3001 that's been drilled to work on a 3002 mount saw.