a9cc56f1____Group_15___2012___GICL_Wiki__3
[0] Exhaust Cover [1] 1 [2] 1 [4] ABS Plastic [5] Light weight, durable, and cheap. [6] Injection Molding [7] Easy and economical way to mass produce this component. [3] 
Prevents larger debris from entering the back of the saw and adds some additional safety (prevents hands from entering). Designed so air can flow through.
Gate 3 - Group 15 - 2012 - GICL Wiki