Scales?

Scales?
 

Balanza literally means 'balance', and báscula scales. I'd probably use báscula, but both are acceptable.

Both are OK

but usually "báscula" it's a electronic/automatic device who gives you the weight (your weight in a pharmacy, the load of a truck, an so on) and a "balanza" it's manual, with two plates, in one plate you palce the thing and in the other plate you have to place different weights in the other plate ( the roman one, in the hand of the Justice)

Saludos :D

Thank you guys so much. You're great. :)