3 Mechanical Interfaces IP67 and above for industrial and ruggedized applications. 3 dom of choices for your needs and requirements. 3 Budgets, pay for what you need. ALTW’s “3-3-3 SPE” mechanical interfaces are all designed and made according to IEEE 802.3bp standard offering three mechanical mating interfaces all IP67 up and above giving you the freedom to choose the interconnects suitable to your needs and requirements for industrial and ruggedized applications.