Sizes: You can use any size, but most usual are: 600x500 and set in template 600x500 as width & height and 300x250 as collapsed width & collapsed height

Description: When delivered, this ad is displayed as any other standard graphic element on the web page. After moving the mouse pointer over the ad, it expands (grows in size) and covers the web page content partially. Clicking the creative redirects users to the landing page.

CTR level: positioning dependent

Vieability rate: positioning dependent