ifMatchSize

If present, the object is deleted only if its size matches the provided size in bytes. If the Size value does not match, the operation returns a 412 Precondition Failed error. If the Size matches or if the object doesn’t exist, the operation returns a 204 Success (No Content) response.

This functionality is only supported for directory buckets.

You can use the If-Match, x-amz-if-match-last-modified-time and x-amz-if-match-size conditional headers in conjunction with each-other or individually.