The Philmac Metric/Imperial End Cap in 25mm / 3/4" size is designed for use with water tanks. Made of corrosion-resistant plastic, this straight-shaped cap is suitable for industrial plumbing and fixtures. With a maximum water temperature of 104 °F (40 °C), this unfinished cap is compatible with both metric and imperial systems, making it a versatile and durable choice for various plumbing needs.