The inside of a computer case is often covered in dust More importantly, dust can settle inside unoccupied PCI & RAM slots Over time, The dusts build-up can become significant enough to cause contact problems with newly installed PCI cards or extra RAM memory With Lamptron's PCI/RAM slotsin addition, The Lamptron's PCI/RAM slots protectors are UV-Reactive, a perfect accessory for systems with windowed cases & UV lighting. Contains: - Ram Slot Protector--3pcs - PCI Slot Protector--3pcs - PCI-E 1x Slot Protector--2pcs - PCI-E 16x Slot Protector--2pcs