Sonance - XPC-10WSQ-T - Visual Experience Extreme 10" Woofer X-Large Micro-Trim Square Adapter with Grille (Each) - Paintable White

Yes, this grille is suitable for outdoor use.

Yes, this adapter is compatible with round speakers.

This grille adapter is made of stainless steel and plastic.

The compatible speaker size for this adapter is 10 inches.

Yes, this adapter enables the use of a square grille with a round speaker.