ok, the box “extent” is not measured in the same way as a mesh. It’s 2 to 1, also you need to be taking a look at the scaling values for a box extent, there is the “unscaled” (i.e. extent/size before scaling is applied), and the scaled size, (size/extent after scaling is applied). I always set the scaled size to one, and then the alter the scaled size of the Box Collision itself.