Good hardness and extremely lightweight: Made of materials, this connector flange offers hardness while remaining incredibly lightweight, enabling easy installation and handling. Screw hole design: Equipped with five 5 mm diameter screw holes for secure attachment to various surfaces. The flange measures 12 x 12 cm with a thickness of 3 cm, providing a sturdy and secure connection. spacing and tube diameter: The distance between each screw hole is 5 cm, allowing ample room for fastening. The round tube diameter is 11 cm, supporting efficient airflow and ventilation. fit for 12038 and 12025 ducting: Specifically designed to accommodate 12 x 12 cm ducting and applications requiring 12038 or 12025 fans, ensuring a precise, snug fit and optimized performance. Use scenarios: Install a compact ventilation run in a 12 x 12 cm ducting system using a 12038 or 12025 fan, where a rigid, lightweight flange is needed for a secure mount. Mount inside an equipment cabinet or wall panel to create a stable duct connection with minimal bulk and straightforward screw attachment. Use in small workshop or enclosure venting where a precise 12 x 12 cm duct connection is required to maintain orderly airflow and reliable fastening.