Transitioning from Cox-rented panoramic WiFi modem/router/whatever to off-the-shelf

I understand the process up to the point of turning in my current modem to Cox. Okay, I drop it off at any specified location, got it... Is that it? The $15/month rental fee disappears within a billing cycle or two?

Will there be any sort of "restocking fee" or something? Termination of rental fee? Or just... Turn it in, the charge disappears?

Thanks in advance.