SM4221 is an SMA male to N male RF adapter from Fairview Microwave designed to enable connections between two incompatible connector types. The adapter operates across a frequency range from DC to 18 GHz with excellent VSWR performance of 1.25:1 maximum and an impedance of 50 Ohms. It features a straight body geometry with gold-plated beryllium copper contacts (0.3 µm minimum plating), PTFE insulation, and brass body with tri-metal plating, ensuring reliable performance across an operating temperature range of -45°C to +125°C. The adapter measures 1.27 inches (32.26 mm) in length and 0.79 inches (20.07 mm) in width, with a weight of 0.08378 lbs (38 g), and supports 100 mating cycles on each connector. This adapter is ideal for general-purpose RF testing and enables between-series connections while protecting expensive equipment connectors from wear during frequent connect/disconnect cycles.