DrB...Boss is best known for car audio amplification and is probably just importing and branding these speakers which appear to be knockoffs of some JBL Pro Series speakers. They are probably reasonably marinized though mtal painted grills tend NOT to hold up very well. I would expect sound quality to be mediocre but perhaps that will suit your needs as not every application needs to be high fidelity.
If you want an alternative...consider these Polks:
Polk Atrium 45 Indoor/outdoor speakers at Crutchfield.com