Letting a class see another object's variables

I have a functional pong game, and I'd like to add powerups (such as increase paddle size). I've created a Powerup class, and I'd like to let it handle all the powerup business. However, I'm not sure how to let my Powerup class see the variables of one of my Paddle class objects. That is, I'd like to use [font=courier new,courier,monospace]paddleLeft.height += paddleLeft.Height[/font][font=arial, helvetica, sans-serif] in my Powerup class to double the size of the left paddle (but leave the right paddle alone). However, paddleLeft [/font][font=arial,helvetica,sans-serif]is an instance of my Paddle class, and it's made in my Game1 class. Is there a way to let my Powerup class know I have a paddleLeft instance, and give my Powerup class access to its variables? I could add parameters to the Powerup constructor, but that doesn't seem efficient. Is there another way?[/font]