Inclusion Criteria:

• Age ≥18 years.
• Diagnosis of OAB-wet (OAB with urgency urinary incontinence) documented by clinical diagnosis
• Baseline ≥1 UUI episode/day averaged over a 3-day diary
• Is on a stable pharmacotherapy for OAB for ≥4 weeks, with intent to remain on their medication regimen for the duration of this study
• Has the ability to complete bladder diaries, questionnaires, and attend follow-up visits
• Cognitively intact adult and able to understand study procedures and provide informed consent independently

Exclusion Criteria:

• Neurologic disease affecting bladder function, including multiple sclerosis, spinal cord injury, Parkinson's disease, or other neurogenic bladder conditions.
• Significant pelvic organ prolapses or other pelvic pathology likely to interfere with bladder emptying, neuromodulation efficacy, or study assessments in the opinion of the investigator
• Active urinary tract infection or unexplained hematuria at screening
• Clinically significant post-void residual volume above threshold (e.g., >100 mL)
• History of, failure of, or current use of neuromodulation therapies, including percutaneous or transcutaneous tibial nerve stimulation, sacral neuromodulation (InterStim), implantable tibial devices (eCoin)
• Intravesical botulinum toxin injections less than 9 months prior to entry into the study
• Pregnancy or plans to become pregnant during study participation, and women of childbearing age not using contraception. A urine pregnancy test will be performed for women of childbearing potential to confirm non-pregnant status prior to enrollment.
• Contraindications to electrical stimulation (cardiac pacemaker or implanted defibrillator without physician clearance, unhealed wounds near stimulation site, metal implants in the ankle region)
• Significant uncontrolled medical conditions, such as unstable cardiac disease, poorly controlled diabetes mellitus, severe peripheral edema, or severe peripheral neuropathy that may affect lower-limb sensation or response to stimulation in the opinion of the investigator
• Pelvic malignancy or prior pelvic radiotherapy.
• Current participation in another investigational drug or device trial, or use of an investigational therapy within the last 30 days
• Known hypersensitivity or intolerance to materials used in the ZIDA device (electrode adhesives, conductive gels)