Product specification fields

Our products have some specification fields that are the same for all the products: lenght, height, width, material, weight, pallet dimensions etc. Not options but simple text field.

How can I add some simple custom specification field (text) to the product
I noticed the product attributes and specification attributes but these are not user friendly.

I want to extend the add product screen with some simple text field lenght, height, width, material, weight etc. Is this possible by default? do I need the install an extension, please help?

Specification attributes would be used.  Please clarify "not user friendly"

to make the label "height: 1200cm" with specification attributes you need 6 clicks... per product.. per field.

If it was a single input field in the 'add product screen' you just type in the value 1200cm.

I think the last is way more user friendly...
Customer just complaint it's to much work.

So it's not possible to make custom input fields in the "add product" screen?

No, it would require customization.