Cleartone Monster Heavy Series are the worlds first guitar strings with both VolumeBOOST™ and ToneLOCK™. VolumeBOOST™ comes from an enhanced core to wrap ratio and extra heavy duty construction in combination with the Cleartones patented volume enhancing treatment. It’s the only string that independent sound labs have proven are louder than even uncoated Cleartone – By as much as 36%! Cleartone ToneLOCK™ allows the strings to last up to 3-5 times longer than traditional strings, but with this patented “No Feel” coating on all 6 strings, you lose nothing and gain everything. Play Louder for Longer. Cleartone is owned by Rock and Roll Legend Phil Everly. The only strings made by someone who actually helped invent Rock and Roll. Available from 9-42 all the way down to Drop A (14-80).