What is this Filter?

I took off the filter next to the Transmission fluid drain plug. Well it got destroyed and I don't know what the heck it was or where to get a new one. It says Oil Filter 38325AA032 on it and also says AT ONLY. Please Help?

2001 Subaru Legacy/OUtback

I found out what it is. It's the transmission oil filter. What the heck? An external filter that looks like an oil filter? These are called spin-type ATF Filters - Part No. 38325AA032. These aren't usually changed when you get your transmission serviced because it doesn't really need to be. They cost about $34. Don't puncture a hole in it like I did mine ha ha ha...