D'Addario EJ45 Pro Arte Nylon Core Silverplated Wound Normal Tension Clear Nylon Classical Guitar StringsD'Addario EJ45 Pro Arte Nylon Core Silverplated Wound Normal Tension Clear Nylon Classical Guitar Strings NORMAL TENSION Silver Plated Wrap Nylon Core Clear Nylon Trebles EJ45 EJ45, normal tension, is D'Addario's best selling classical set, preferred for its balance of rich tone, comfortable feel and dynamic projection. All Pro Art treble strings are computer controlled by an X Y laser micrometer which performs diameter and tension measurements,