A stent graft delivery device includes a handle body, a distal handle, a proximal handle, a guidewire lumen, a nose cone, a rigid outer catheter, a graft push lumen, a sheath lumen, an inner sheath and a locking ring. The locking ring is switchable between an advancement position and a delivery position. The stent graft delivery device is employed in methods for endovascular delivery of stent grafts.