• Adult male between ≥40 and ≤80 years of age

• Subjects with a history of self-reported erectile dysfunction lasting for over 6 months and not more than 5 years.

• The subject is PDE5i responsive, meaning he is able to achieve and maintain an erection under the effect of the maximal dosage of PDE5i

• The subject has been in a stable heterosexual relationship for over 3 months prior to enrollment.

• A minimum of 4 sexual attempts during the last two weeks prior to enrollment.

• Abstinence from taking PDE5 for two weeks (washout) after enrolment and 2 weeks before each follow up visit/call.

• IIEF-EF score between 11 and 25.

• Testosterone level 300-1000 mg/dL within 1 month prior to the enrollment/baseline.

• A1C level ≤ 8.5% within 1 month prior to enrollemnt/baseline.

⁃ Subject has at EHS score ≥ 1 (natural tumescence during sexual stimulation).

⁃ The subjects should understand the information provided about the investigative nature of the treatment, possible benefits and side effects, and are willing to sign the Informed Consent Form

⁃ If the FirmTech Ring is provided, the participants must be willing to use the ring according to the instructions.

⁃ The subjects should be willing to comply with the study procedure and schedule, including follow up visits.

⁃ Agreement/ability to abstain from erectile dysfunction medications or any device treatments for the duration of the study, i.e., the time between the treatment visit and the final study visit.