NEC NP44LP Filter original filter for NEC NP-PE523X, NP-P554U, NP-P554W, NP-P474U, NP-P474W, NP-P603X, NP-P604X, NP-PA5520W, NP-CF6500X, NP-CF6600U, NP-P603X, NP-CB4600U, NP-P523X