Muestra la cinta exprés y el dispositivo asegurador.

Here, muestra is most naturally understood as a command: Show the quickdraw and the belay device.

For mostrar (to show), the tú command is muestra.

This form is also identical to the:

• él/ella present form: he/she shows
• usted command: show (formal)

So by itself, muestra can be ambiguous. In a sentence like this, context usually tells you it is an instruction or command.

The sentence does not explicitly say the subject, which is very normal in Spanish.

Because this looks like an instruction, the implied subject is probably:

• tú if it is an informal command
• possibly usted if the situation is formal

Spanish often leaves out subject pronouns when they are understood from the verb form or the context.

These are the definite articles:

• la = the for a feminine singular noun
• el = the for a masculine singular noun

So:

• la cinta exprés because cinta is feminine
• el dispositivo asegurador because dispositivo is masculine

The gender is determined by the noun:

• cinta is feminine
• dispositivo is masculine

The adjective exprés does not change that.

In Spanish, adjectives usually come after the noun, especially in technical or descriptive language.

So:

• cinta exprés
• dispositivo asegurador

This is the normal order for a neutral, descriptive meaning.

Putting the adjective before the noun is much less common and often changes the tone or emphasis. In this technical context, noun + adjective is the expected pattern.

Yes, exprés is functioning as an adjective here.

It describes the type of cinta. In technical usage, especially in climbing contexts, cinta exprés is a fixed term.

A useful point for learners: exprés often stays the same in form and does not behave like a typical adjective such as rojo/roja.

So you get:

• cinta exprés
• cafetera exprés

The form exprés itself does not usually change for gender here.

The written accent shows where the stress falls: ex-PRÉS.

Without the accent, Spanish spelling rules would suggest a different stress pattern. The accent is there to mark the correct pronunciation.

So the accent is not optional; it is part of the standard spelling of exprés in this use.

Spanish often uses an adjective where English might use a noun or a different structure.

Here, asegurador is an adjective meaning something like securing or belaying, depending on context.

So:

• dispositivo asegurador = a securing/belay device

This kind of noun + adjective combination is very common in Spanish, especially in technical vocabulary.

You could sometimes find other ways of expressing similar ideas, but dispositivo asegurador is a compact technical phrase.

Y means and.

Spanish changes y to e before words that begin with an i sound:

• padre e hijo

But here the next word is el, which begins with an e sound, not an i sound, so it stays:

• cinta exprés y el dispositivo asegurador

So y is correct.

Yes, grammatically it could.

Muestra can mean:

• he/she shows
• you show (formal command)
• show (informal tú command, in context)

Without more context, the form alone is ambiguous. However, if this appears in instructions, a manual, or a training exercise, the command reading is the most likely one.

In standard Spanish, the articles sound much more natural here:

• Muestra la cinta exprés y el dispositivo asegurador

Leaving them out would usually sound unnatural unless you were writing labels, notes, or very compressed checklist-style language.

Spanish often uses definite articles in places where English may or may not use the, especially when referring to specific items in an instruction.

Here it is best understood as an adjective modifying dispositivo.

The main noun is:

• dispositivo

And asegurador describes what kind of device it is.

In other contexts, related forms can behave differently, but in this sentence the structure is clearly:

• noun + adjective = dispositivo asegurador

Yes, it can sound natural, especially in a technical, instructional, or training context.

A native speaker might choose slightly different terminology depending on the exact climbing context, but grammatically the sentence is fine and the structure is very natural for giving instructions:

• verb command + object 1 + y
  • object 2

So for a learner, it is a good example of how Spanish gives concise instructions.