The GPM M39.0X4.00 GO 36.4020MM is a precision gauge from Field Tool Supply, designed for measuring and verifying dimensions in machining applications. This gauge features a M39.0X4.00 thread specification, ensuring compatibility with various systems. Constructed from high-quality materials, it offers durability and accuracy in measurements. The gauge meets industry standards, making it suitable for professional use. Its compact design allows for easy handling, making it an essential tool for machinists and engineers seeking precision in their work.