Yes, Wonder Under is fusible web. Steam a Seam, and Steam a Seam 2 are also fusible webs. There are many different brands available.
If you haven't used fusible web before, please be careful not to get it on your iron. There are silicone pressing sheets that can be used like a pressing cloth to protect your ironing board and iron. If you don't have one, you can use parchment paper.