Know when the player is close, and presses a button?

Ok, So In a previous post, (I made) I was very much helped, Thank you to everyone :D

Anyways so they helped me with the Input function (Changing a Model/Parts Transparency, and NoCollide, when pressing a key (e)

I was wondering, what should I do, to where the player has to be atleast 1-3 (Studs?) away from the Model, to make it transparent.

Ex. Im half way across the map, therefore nothing happens

Ex. #2 Im 1-3 Studs away from the Model, I then press E, and the Model turns transparent, and then It becomes NoCollide.

Just need help with the player detection/Distance part.

Thanks :D