Why does the 60V MAX DCD460 Stud and Joist Drill have two speeds?

The drill has a low speed (setting 1) which is 0-300 RPMs and a high speed (setting 2) which is 0-1250 RPMs.

The high speed should be used for smaller holes such as; 1-1/2” flat boring into wood, 1-1/2” ship augers, and 2-9/16” self-feed bits.

The low speed should be used for larger holes such as; 6-1/4” hole saws and 4-5/8” self-feed bits.