It's not a USM/HSM/SDM/SWM motor, it's just a plain old noisy micromotor.
ALL Canon lenses need some sort of motor in the lens, so it's either a USM type (of which there are a few different) or a micromotor. Any Tamron lens for Canon uses a micromotor.
For Nikon, it's either a motor built into the lens or the body (much like Pentax)
What Nikon did is remove the in-the-body motor on the D40/D40x/D60, so to autofocus, you NEED a lens with a motor in the lens. This is either one of the HSM (for Sigma) or SWM/AF-S (for Nikon). Tamron and Sigma have been either updating or newly releasing some of their screwdriven lenses (of which ALL Tamonr lenses were originally for Nikon) with the same micromotor they use in the Canon mounts (ie NOT HSM)
Yeah, I know it's confusing, but I used to shoot Pentax, now shoot Canon, and my Dad shoots Nikon so I've done a little reading on the subject
Originally posted by Venturi That puzzles me too "(Built-in Motor)". Didn't think Tammy made any sonic drive lenses.