For the treatment of the Great Saphenous Vein, the CR45i catheter is used. This extremely flexible 6 French catheter with a 5mm non-isolated tip allows a smooth insertion. The catheter will be pulled back gradually until the entire vein is closed. GSV and SSV ablation with EVRF is minimally invasive side effects such as pigmentation, superficial thrombophlebitis, or deep vein thrombosis (DVT) are very rare. Patients experience minimal discomfort and normal daily activities can be resumed within one day appear.