Cat 299D3 Hydraulic System Type

I have a 2021 Cat 299D3 XE and I'm having to order a solenoid valve block for an attachment thats gonna be used on it, but need to know if it's an open loop or closed loop system. I've searched on Google and can't seem to find a solid answer and can't even find the answer in the owners manual. I believe it's closed loop, but can anyone confirm or deny that? Thanks!