Spring Arm Friction Arm
Spring Arm:- One handed adjustment.
- No sagging of magnifier arm or shade.
- Shade and arm stay where positioned.
Friction Arm:- Requires both hands to position product correctly - one hand to support the magnifier and the other to adjust the knobs.
- Knob tension is difficult to regulate - too loose and the magnifier head and arm will sag or can suddenly drop onto the work surface; too tight and you risk damaging the threaded knobs.