The ALC-480 provides two addressable (SLC) loops for MRI-4000 Series addressable devices, 240 devices per loop, 480 devices total via the Loop Adder. If an ALC-480 Dual Loop Adder Module is used with the MR-401, one ferrite is required for each loop. The two ferrites are packed with the ALC-480. Place the wires coming out of Loop 1 through the ferrite and loop around the ferrite once and back out to connect to devices. If using Loop 2, also place the wires coming out of Loop 2 through the second ferrite and loop wires around the ferrite once and back out to connect to devices.