To function properly, a tonearm must:
1. Hold the cartridge perpendiculer to the record.
2. Adjust to set the arm parallel to the record.
3. Track at the weight of your choosing.
4. Move through the record with no friction.
That's all a tonearm needs
to do, and it should be able to fulfill
using a minimum of parts and pieces.
The tonearms are available in 9" and 12" lengths. The 9" arm
has an anti-skate device which may, or may not, be needed.
The 12" arm does not skate.