When sourcing Neodymium (NdFeB) magnets, the most critical factor is the Grade (e.g., N35, N52, N42SH). The 'N' number represents the Maximum Energy Product (BHmax), which determines the magnetic strength, while the letter suffix indicates the Maximum Operating Temperature (e.g., 'SH' can withstand up to 150°C). For oval shapes, you must specify the Length, Width, and Thickness, as well as the Direction of Magnetization (usually axial or diametrical). Ensure the Remanence (Br) and Coercivity (Hcb/Hcj) meet your specific application requirements.