This should be an easy question. I just purchased Atrium 45 In/Out speakers from a Polk certified on-line dealer. The speakers arrived with the included mounting brackets but only had one of the screw-in devices that secure the speaker to the bracket. I only got one per speaker. I have not been able to find out if this is all that is supposed to be included or if I am missing 2 screws. There is certainly a threaded opening that has nothing to secure the speaker on one end. Thanks for responses.