I’d like the ability to manually adjust both frequency (Hz) and pulse width (µs) on this TENS unit. Different settings produce very different physiological effects—for example, low-frequency stimulation can promote longer-lasting pain relief through endorphin release, while higher frequencies are better for immediate pain blocking. Having control over these parameters would allow users to tailor treatments to their specific conditions, pain levels, and therapeutic goals rather than being limited to preset modes. This added flexibility would significantly improve effectiveness for more informed users and those managing chronic conditions.