Inclusion Criteria:  Subject must demonstrate clinical signs and symptoms that are attributable to the targeted lesion and are consistent with the diagnosis of acute ischemic stroke (AIS), as confirmed by a neuroradiologist (or equivalent expert), using appropriate imaging. Arterial occlusion of ICA, MCA-M1 or MCA-M2. Female or male subject, who, at the time of consenting, is aged between 18 and 80 years, inclusive. Within 6 hours of stroke symptom onset, subject must have undergone treatment initiation (vascular access through puncture or cut down). Signed Informed Consent Form (ICF) completed by subject or subject's legal representative.  Exclusion Criteria:  1. Functional dependence prior to stroke onset, defined as a pre-stroke modified Rankin Scale (mRS) score of ≥2. 2. Subject's baseline NIHSS score <2 or >25. 3. History of severe head injury within past 90 days with residual neurological deficit, as determined by medical history. 4. Pre-existing neurological or psychiatric disease that would confound the neurological or functional evaluations, e.g. dementia with prescribed anti-cholinesterase inhibitor. 5. Seizures at stroke onset if it makes the diagnosis of stroke doubtful and precludes obtaining an accurate baseline NIHSS assessment. 6. Subject has a known hemorrhagic diathesis, coagulation factor deficiency; or, is on oral anticoagulant therapy and has an International Normalized Ratio (INR) >3. 7. Subject's baseline platelet count is <30*10^9/L. 8. Subject's baseline glucose is <50 mg/dL (2.78 mmol/L) or >400 mg/dL (22.2 mmol/L). 9. Renal failure, as defined by a serum creatinine >3.0 mg/dL (264 µmol/L) [NOTE: subjects on renal dialysis may be treated regardless of serum creatinine levels]. 10. Severe, sustained hypertension (SBP > 185 mm Hg or DBP > 110 mmHg) [if the blood pressure can be successfully reduced and maintained at the acceptable level, using medication, the patient can be enrolled]. 11. Subject has known allergy or contraindication to one or more of the following: anti-platelet drugs; contrast dye; and/or, local or general anesthesia. 12. Subject has known allergy to nickel, cobalt chromium, tungsten, platinum or other metal that may be a component of a required medical device needed for treatment. 13. Subject is generally unsuitable for endovascular intervention or anesthesia. 14. Subject has had major surgery within the previous 30 days 15. Subject is an active participant in another drug or device treatment trial for any disease state; or, subject is expected to start participation in another drug or device trial while enrolled in this protocol. 16. Subject currently has infective endocarditis or other severe, active bacterial infection. 17. Subject's life expectancy is less than 6 months. 18. Female of childbearing potential who is known to be pregnant and/or lactating or who has a positive pregnancy test on admission.  Imaging Exclusion Criteria:  19. Subject has CT scan or MRI evidence of the following:  Significant mass effect with midline shift. Evidence of intracranial tumor, except small meningioma. Evidence of intracranial hemorrhage. Evidence of internal carotid artery flow limiting dissection. Suspected cerebral vasculitis. Suspected aortic dissection. Occlusions in multiple vascular territories (e.g., bilateral anterior circulation, or anterior/posterior circulation) or clinical evidence of bilateral strokes or strokes in multiple territories. 20. The presence of a large completed territorial infarction by non-contrast CT (NCCT), defined as an Alberta Stroke Program Early CT Score (ASPECTS) ≤5.  21. Other unusual morphology or lesion that might interfere with device use, including but not limited to the following:  Carotid dissection Vasculitis Aortic dissection Aneurysm  No transfemoral or alternative access, such as:  Severe intracranial tortuosity Severe intracranial vasospasm, unresponsive to pharmacotherapy. Other anatomical or clinical conditions contraindicated for access. 22. Anterior circulation strokes involving > 1/3 of the MCA territory, as determined by hypo-density on the baseline non-contrast CT, or low CBV on CT Perfusion imaging, or restricted diffusion on DWI images. 23. Thrombotic occlusion in the posterior circulation arteries (vertebral, basilar, etc.) 24. Intracranial stent implanted in the same vascular territory that would preclude the safe deployment/removal of the thrombectomy device.