(C#) Collider to collider2d

I'm trying to figure out how to change this to a collider2d format. I'm using this code in conjunction with some raycasting elements.

 box = new Rect(
 collider.bounds.min.x,
 collider.bounds.min.y,
 collider.bounds.max.x,
 collider.bounds.max.y
 );

I can't find an equivalent function to bounds for collider2d. I thought maybe shapeCount but it didn't work to just change it to that and there is no documentation for it.

So yeah if anybody could help me out that would be awesome.