Can someone tell me what C0 and C1 properties are?

[BenMactavsin]

What exactly are .C0 and .C1? (Mostly .C0)

C0 and C1 are exactly what you said it is: the CFrame offset between the two parts in a weld. https://developer.roblox.com/en-us/api-reference/property/JointInstance/C0 C0 is Part0’s offset, C1 is Part1’s offset. So, if I’m remembering right, changing C0 moves Part0, while C1 moves Part1 (I may be wrong on this, I haven’t tested for a while).