Material: Copper + POM wheel, thickened copper rod, wear-resistant, rust-proof, and corrosion-resistant, making the product more durable and long-lasting. Easy installation, fewer parts for pulley installation, simple operation, and lightweight installation. Wheel size: Shower door roller with a diameter of 23 mm, suitable for glass doors with a thickness of 4-6 mm. Provides a mounting opening of 15-17 mm. Wheel features: High load-bearing capacity, ultra-quiet and stable push-pull light drive, labor-saving and safe to use. Suitable for most shower rooms and steam rooms.