Double Check your mower Model, On the 10640 there was no alternative blade offered. The standard blade is a high lift that should work fine for bagging or Mulching. However no mulching plug is listed or incorporated into the chute cover so this mower is not design to mulch. Although you could theoretically mulch by removing the bag, grass will build up in the chute and cause the grass to clump under the mower leaving a bit of a clean up chore.I am looking for a mulching blade for my mower, # 10640, I bought the mower used and do not want to bag. Is one available?