I purchased these at Unidy this summer for a golf competition, costing around 12,000 yen for both. I've only used them once outdoors since then. The battery lasted through one round of golf. I haven't tested the strongest setting. The best one is the type that blocks sunlight, perhaps better suited for stationary tasks rather than walking around. The size is a bit large for the seller, who is 176cm and 80kg. I want to offer them at a bargain price for someone who can use them. I will send them after house cleaning.