How do I assign a template to multiple items?

After importing some data, I need to change the item template in bulk/.
I have used the category feature that lets me assign templates to a given number of categories at once, but I cannot find the equivalent tool to do the same with items.

the sad thing is that I think I have already done it one but I forgot how to do it. Right now I have my category pages displaying one template while my item pages display a different template. I could leave it like that, but this seems like such a simple thing to do I am sure I am missing something.

Thank you

You only need to change this in one place:

-- each Content Item Type defines a default template to you for all items of the type (it is at bottom right of content Type Edit form)

-- NOTE you can override (in each item) the predefined template via Content Type, but it is recommended not to do it unless it is really necessary

Does this mean that when I create a new template I should also create a new "type"?

My situation is this:

1) I have a template called "products" and one called "product_list"

2) In my "types" I only have a type "product" but I don't have a type product_list.

3) Some items need to use the "product" template but many otehrs need to use the product_items template.

Right now, while waiting for the response I went and applied to each item the template product_items. I knew there was another solution, but unfortunately I had to demo the site and I needed the different templates to be assigned.

Since in the future I may need to use this again, is the proper procedure to create a "type? each time I create a new template?

Otherwise, if I import a bunch of records what is the proper procedure to assign them to the right template?

You can assign a template to multiple Content Types, if a content Types does not have some fields assigned to it, then will simply not be displayed not be displayed when item is viewed in frontend

Un type you allow template sélection (in right colum bottom slider)
And same place for each item
Regards