Make sure the interface card you mate with the Line Unit is a Campus-RS interface card. The Campus-RS Line Unit is not compatible with previous versions of Campus interface cards. SURGE PROTECTION To protect you and your Campus-RS devices, ADC recommends the use of a dual line Network Interface Device (NID) with a gas tube or solid state composition. The NID can protect both Campus-Star chassis and Campus-RS Desktop Units. Most lines leased from your local telephone company already have protecti