The watch clasp is the one that holds the watch securely on your wrist. The type of clasp depends on the model and material of the watch. Some brands even play with the style of clasp they use to incorporate it into the overall design of the watch.
U-Boat Capsoil Darkmoon Soleil with tang buckle
The buckle is the most common fastener and is usually found on leather, textile and rubber straps. They can be found with a single or double pin which is related to the design of the watch. The application is the same as the belt buckle. This allows you to adjust exactly how you want your watch to fit, without having to resize it.
Montblanc 1858 Iced Sea Automatic Watch with push buttom clasp
This mechanism is very common in metal or steel watches and can be single or double. The single push-lock works with one pusher that opens the latch and the double push-lock, as the name suggests, works with two pushers.
Push-button clasps can be of the butterfly type, i.e. the strap opens in opposite directions and does not split at all. The butterfly is notable for its elegant appearance, because when closed, the "wings" are almost invisible.
Junghans Max Bill Handaufzug Manual Winding Watch with foldover clasp
This buckle is generally used for stainless steel or milanese bracelets; it is a latch that closes around a bar. It is opened by gently lifting the clasp and disengaging the latch bar.
In addition to the function of the clasp on a watch, the clasps are part of the design and quality of the watch. It all depends on the intended use of the watch and the model.
