The Tension Lover E-Stim Powerbox, a quick-start guide, 2 electrode cables, 4 self-adhesive electrodes and 1 USB charging cable. Mystim says the self-adhesive electrodes are flexible and can be used multiple times.

Use the included electrodes or e-stim toys that connect via the Mystim round plug or a 2 mm plug. With two channels you can run two at the same time, each at its own intensity.

Program 1 lets you set pulse width, frequency and intensity freely. Programs 2 to 7 run preset patterns that move between tingling, pulsing and thrusting sensations, and programs 8 to 10 are training programs. Mystim advises finding the right intensity in program 1 before trying the others.

The built-in 3.7 V 500 mAh lithium-polymer battery runs for up to 35 hours with one channel in use and holds a standby charge for about 5 months. Charge it with the included USB-C cable and a standard adapter; the device cannot be used while it is charging.

Mystim says to use it below the belt only. People with electronic or metallic implants such as pacemakers, heart defects or cardiac arrhythmia, or epilepsy must consult a doctor first, as must anyone with a copper coil or chain. Never let current flow through the brain or heart, never stimulate the throat, do not use it during pregnancy, and use it only on healthy skin.

Place the electrodes or insert the toy first, then turn the channel’s knob clockwise until it clicks, which also raises the intensity. Mystim says to set the intensity only after the toy is in place and to turn it off before removing it.

Mystim gives a 12-month warranty on the Tension Lover 2.