The two recommended formats are the Mid Page Unit (MPU, 300×250 pixels), and the Leaderboard (728x90pixels.) There are other formats that are popular with advertisers and you may, in some cases, find it easier to fit other formats into the page design of your site.
These formats are called Skyscraper (160×600 pixels) and Mobile Banner (300×50 pixels). Muslim Ad Network can work with any IAB standard size so be sure to ask for other options if these do not fit your site.