Inclusion Criteria:  Candidates must meet all of the following inclusion criteria to be considered for enrollment in this study.  Age 2 to 10 years old (± 6 months). Male or female. Subject has a native or repaired right ventricular outflow tract. Subject has been recommended for surgical pulmonary valve replacement by treating clinical team (cardiologist and cardiac surgeon).  Subject has at least one of the following echocardiographic findings:  Severe pulmonary stenosis (defined as RV to PA peak instantaneous gradient ≥60 mmHg); Moderate or greater pulmonary regurgitation (defined as (vena contracta jet width/square root of BSA) ≥2.98 mm/m2). Moderate or greater pulmonary stenosis plus moderate or greater pulmonary regurgitation. Subject's body size is suitable for implantation of a study device ranging from 12.7 to 22 mm (internal diameter). Subject's pulmonary artery length (measured from pulmonary valve annulus to pulmonary artery bifurcation) is at least 25 mm. Subject and parent/legal representative, where appropriate, are willing to provide informed written consent. Subject and parent/legal representative, where appropriate, and treating physician agree that the subject will return for, and comply with, all required study assessments and follow-up visits.  Exclusion Criteria:  Candidates will be excluded from the study if any of the following conditions are met:  Subject requires valve replacement in a non-pulmonary position. Subject has a prosthetic valve at other valve position or will need a prosthetic valve at other valve position (i.e., anticipation for additional valve replacements needed within 3 years). Subject has pulmonary arterial hypertension (defined as mean PA pressure ≥25 mmHg). Subject has pulmonary atresia and major aortopulmonary collaterals. Subject has significant peripheral pulmonary artery stenosis. Subject requires a concomitant non-cardiac surgical procedure. Subject has an active infection requiring current antibiotic therapy (if temporary illness, subject may be a candidate 4 weeks after discontinuation of antibiotics). Subject has active endocarditis or a history of infective endocarditis. Subject has renal insufficiency as determined by a serum creatinine (S-Cr) level ≥2.5 mg/dL within 60 days prior to the Screening Visit, or has end-stage renal disease. Subject has leukopenia (defined as a white blood cell (WBC) count <3.5 x 103/µL) Subject has acute or chronic anemia (defined as hemoglobin (Hgb) <10.0 g/dl or 6 mmol/L). Subject has thrombocytopenia (defined as platelet count <50 x 103/µL. Subject has known a hypersensitivity to anticoagulants and antiplatelet drugs. Subject has a known autoimmune disease or receives immunosuppressant and/or immunostimulant drugs. Subject needs emergency cardiac or vascular surgery or intervention. Subject has, in the opinion of the Investigator, a life expectancy of less than 5 years. Subject or parent/legal representative refuses blood transfusions. Subject has medical, social or psychosocial factors that, in the opinion of the Investigator, could impact safety or compliance with study procedures. Subject is participating in an investigational study of a new drug, biologic or device at the time of study screening.