The 4MP-6FP STR Expander by Fittings Unlimited Inc is a specialized fitting designed for expanding pipe connections. With a 4mm size and a 6mm connection, this expander is ideal for various plumbing and HVAC applications. Its durable construction ensures long-lasting performance, while its design allows for easy installation and secure connections. This fitting complies with industry standards, making it a reliable choice for both professional and DIY projects. Perfect for enhancing system flexibility and efficiency.