The plastic square cap is designed to fit 40x40mm square tubes with a substantial wall thickness of 3-5mm. This cap serves as a protective cover for the end of the tube, providing a secure and reliable seal. Made from high-quality plastic, this cap ensures durability and long-lasting performance. It offers a snug fit and effectively prevents dust, dirt, and moisture from entering the tube. With its easy installation process, this square cap is a practical solution for various applications, including industrial projects, construction sites, and DIY crafts. Enhance the functionality and appearance of your square tube with this plastic square cap.