1999 Forester - CV Axle Seal?

Hi everybody, made a new account to ask a question for you all. My mom has a 1999 Forester that my dad is currently doing some work on. He's looking for a specific part and is having trouble finding it online. I'm not very car-savvy myself, but I thought you guys might be able to help.

He's looking for what he says is a CV axle seal or transaxle seal. From my understanding, it's a seal that sits between where the axle enters the transmission. Like I said, we're having trouble finding the part we need online. Any chance you guys could give me a part number or point us in the right direction?

Thank you all so much!