Uh-huh.
So if you use a rubber double curved case , you must use rubber push-buttons. So if we're going for rubber then we have to decide for the case. Um and if we choose double curved then we have to go for rubber push-buttons.
Well , we're gonna go with  I think we've decided that it's gonna be a rubber case so
So it's a constraint. Yeah , but is it a double curved one or not ?  If it's not a double curved , then we've got the choice for the push-buttons , if it's a double curve , we've gotta go for rubber push-buttons. If that makes sense.