I get lots of hits for "Caja y armys de acero"

CAJA
Parte del reloj que encierra la máquina y esfera, de la que salen unas asas por la que se sujetan la correa o el armys. Pueden ser de acero, chapadas, caucho, etc y con numerosas formas, redondas, cuadradas, ovaladas, etc.

Se llama armys, al brazalete o cadena que sirve para sujetar y abrochar el reloj a la muñeca. Pueden ser de acero, metal chapado, etc, pero siempre metálicas.

http://www.cronojoyas.com/sections.php?op=viewarticle&artid=...


Metal Watch with Stainless Steel Case and Band
All 904L Stainless Steel; Solid stainless steel casing and band

I suggest you image google for "swissarmys" and you'll find two watches. A friend of mine who ownes a jewerly shop just told me armys or swissarmys is a brandname...

"terminal de caja" *should* be "box clasp," but I'm suspicious, because it is not the sort of clasp that one would put on a heavyweight man's watch, or with a rubber watchband. My suggestion is based on the possibility that the text is not describing a standard buckle that you'd normally see on a rubber watchband, but something like this:

http://www.righttime.com/oris/watchbands/rs42501s.jpg

that is similar to the square clasps used on military webbed belts.