A custom soundtrack for Payday 2 that gives you the Risk Of Rain 2 OST.

The songs used are as follows
Stealth: They Might As Well Be Dead
Loud: You're Gonna Need a Bigger Ukulele

The link below showcases them if you wanna see what it's like before downloading.
https://www.youtube.com/watch?v=EE7xXPl4N9g