EXL120+ string sets from D'Addario with its 9.5 gauge high E, is the ideal "step up" set for players who are moving up from 9 to 10 gauge sets. Additionally, it's great for balancing tension between various scale length guitars. If you play 9s on a 25-1/2" scale guitar, try EXL120+ for your shorter scale length instruments to maintain more consistent feel and playability.