This is a product with a defect. The face has been modified with deep grooves. High rebound, deep grooves to prevent topping, and it will stop on the green. Modified to reduce loss from grass catching in the rough and ensure stable flight. This is a hand-made modification, so there may be some unevenness in the grooves. This is a special modification that most professionals cannot do. Although it's unlikely to be noticed even if it's modified, please refrain from using it in official competitions. I can accompany you for a test drive and round at Tsuchiura One-Way Golf Course, which is often featured on YouTube.