Unless rubbing your nipples is part of your job, anyway.. Andractim testosterone gel is a topical gel, which comes in a tube, containing 80x 25mg doses of DHT. Absorption rate is going to be similar to testosterone gel, or roughly 10%, so youre applying 2.5mgs of pure DHT to your nips every time you use this stuff.
Servos are also used in in-line manufacturing, where high repetition yet precise work is necessary. Of course, you don't have to know how a servo works to use one, but as with most electronics, the more you understand, the more doors open for expanded projects and projects' capabilities.
They are also used in powerful heavy-duty sail boats. Servos are rated for Speed and Torque. Normally there are two servos of the same kind, one geared towards speed (sacrificing torque), and the other towards torque (sacrificing speed). A good example of this is the HS-625MG servo and the HS-645MG servo.