This is the Watch Protector Glass Guard. It's a protector that you thread onto the strap to protect the glass. It is no longer in production. It is a deadstock item. This is the small size. It fits up to approximately 18mm. The color is black. It can be used widely, from divers' watches to automatic and manual-winding watches, and even regular watches. How about using it for everyday wear? It's lovely (*^^*) I am decluttering, so I am selling many items I collected in the past and watches with unconfirmed functionality!! Please be sure to check my profile before purchasing. This is a glass guard to prevent scratches on your watch glass. Please use it by threading it onto the strap. It is deadstock, but it is a product from several decades ago, so please understand. This is the large size. It's especially recommended for the upcoming summer (*^^*)