Specifications: The T-nut is rust resistant with the carbon steel material and nickel-plated surface treatment. This 20 series T nut is special fasteners for European standard profiles (T-slots), and widely used in CNC routers, robotics projects, industrial frame structures, etc. It is easy to use, you just need to put the nut head into the groove and rotate it 90 degrees clockwise, it can be automatically positioned and locked. Item Name: T Nut Material: Carbon Steel Surface Treatment: Nickel-plated Quantity: 50Pcs Model: M3, M4, M5 Features: Easy to Install, Nickel-plated, T Type Nut Size: 1.03cm x 0.6cm x 0.5cm/0.41" x 0.24" x 0.2" (Approx.) Notes: Due to the light and screen setting difference, the items color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 50 x T Nuts