Who invented the deployant clasp?
A deployment clasp, also called a deployment buckle, a deployant clasp, a butterfly clasp, or an invisible double locking clasp is an expanding metal mechanism designed to fasten a watch band with a fitted look. Invented in 1910 by Louis Cartier, deployment watch clasps fold and unfold to provide a tailored fit.
Deployant Clasp
Deployants (also called deployment) clasps are common in metal watches as they perfectly fit their aesthetics and mechanism. This type of clasp folds into thirds, allowing for a wide size when putting on or taking off the watch.
Instructions on how to use your deployment clasp - YouTube
Deployment clasps are far more secure on your wrist than conventional leather buckles. Because of their metal construction, deployment clasps hold very securely, no matter what you throw at them. On top of that, butterfly-style deployment clasps lock in two different places, so your watch won't be going anywhere.
Often called a deployment clasp, the deployant was invented by Louis Cartier (the grandson of the founder) in 1910. The name comes from the French word déployant, which means to unfold, extend, or unfurl.
Adjective. deployant (not comparable) Of the clasp of a wristwatch: having an expanding metal mechanism used for fitting the two ends of the strap together.
How to use a deployant clasp - YouTube
How to Install a Deployant Clasp - YouTube
A deployant buckle is a buckle on either a strap or bracelet that allows the strap or bracelet to be widened for putting on or taking off without unbuckling.
A butterfly clasp consists of two metal hinges that open to the right and left – just like a butterfly spreading its wings. Some butterfly clasps are available with push button release.
How does a butterfly buckle work?
The butterfly clasp is a popular variant of the deployant clasp, which, like the regular version, is a pressure-sensitive system. The peculiar feature of this clasp is that it almost involves two deployant clasps: which symmetrically fold into each other, meeting at a joint.
A watch band buckle or a watch band clasp is either the opening part or the widening part of a watch strap. Its main purpose is to connect and secure two strap ends around your wrist and, usually, to make opening and fastening quick and easy.

Watch straps: Butterfly clasp, folding clasp & more - YouTube
How to Open a Butterfly / Hidden Folding Clasp by AuthenticWatches ...
Deployant is absolutely the correct term for a fold out watch clasp. Deployment is a word that's used mistakenly more frequently.
How to buckle your watch strap - YouTube
Ardillon / Tang buckle
Usually made of stainless steel, the Tang buckle is what you would commonly see in leather and textile watches. The Tang Buckle has a pin that secures the watch to your wrist through the holes on the leather.
Deployant is absolutely the correct term for a fold out watch clasp. Deployment is a word that's used mistakenly more frequently.
A deployant buckle is a buckle on either a strap or bracelet that allows the strap or bracelet to be widened for putting on or taking off without unbuckling.
- Velcro Straps.
- Tang Buckle.
- Deployment Clasps.
- Push Button Deployment Clasps.
- Fold-Over Push-Button Deployment Clasps.
- Double-Locking Clasps.
- Butterfly Clasps.
- Safety Strap Clasp.
How does a butterfly clasp work?
How to use a butterfly clasp on a watch strap - YouTube
To adjust a deployment clasp, you'll need to unfold the hinged metal sections and set the length of the band. Once you've fitted the band to your wrist, there's no need to adjust it again—simply snap the deployment clasp open and closed each time you want to wear your watch.
How To Install A LIV Deployant Clasp | #LIVWatches​ - YouTube
How to Install a Deployant Clasp - YouTube
How to Open a Butterfly / Hidden Folding Clasp by AuthenticWatches ...