Violet Wand

• 30k volts at high frequency

PSG-MAX

General Limits/Ranges

• Current ranges for sensation, pain, and damage. Resistance ranges
• Official product: Fine TENS
• several official products
• experimentally determined frequency and voltage
• 100mA = heart stopped
• lots of ranges, 75mA = loss of control in heart, tissue burning is at 5A
• TONS of references, Looks like it's well-advised to stay <20mA, and very likely stay <10mA.
• this dude says 9volts is definitely enough

Warnings & Precautions

• FDA's official list
• Thorough play-oriented list
• Advice from a EE. Encourages not to try this at home.