I've not looked at the piece under a magnifying glass, but please examine the images provided, and excuse the distracting glare. I substituted a suede band for the original, which I found unimpressive. Alas, after years of wearing very thin watches, I found this one beautiful but a bit hefty for my wrist. The referenced watch is a genuine Seiko Alpinist.
As far as authenticity, the guarantee is indefinite and unreserved. Best wishes and please have a look at my other listings. The item "Seiko Alpinist Automatic Movement Green Dial Men's Watches SARB017" is in sale since Wednesday, September 23, 2020. This item is in the category "Jewelry & Watches\Watches, Parts & Accessories\Watches\Wristwatches". The seller is "bonfim59" and is located in Reston, Virginia.This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, Sweden, South Korea, Indonesia, Taiwan, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Mexico, New Zealand, Singapore, Switzerland, Norway, Croatia, Malaysia, Chile, Colombia, Costa rica, Panama, Trinidad and tobago, Guatemala, Honduras, Jamaica, Antigua and barbuda, Aruba, Belize, Dominica, Grenada, Saint kitts and nevis, Saint lucia, Montserrat, Turks and caicos islands, Barbados, Bangladesh, Bermuda, Brunei darussalam, Bolivia, French guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Cambodia, Liechtenstein, Sri lanka, Luxembourg, Monaco, Macao, Martinique, Maldives, Nicaragua, Pakistan, Paraguay, Uruguay.