Martin MSP6200 SP Lifespan 80/20 Bronze Medium Acoustic Guitar Strings<div style="text-align: left;"><strong>[Product Information]</strong><ul><li><span class="a-list-item"> Treated with Martin's Clear tone proprietary technology for a longer lifespan than regular strings </span></li><li><span class="a-list-item"> Designed to repel the oils and dirt that can deaden strings </span></li><li><span class="a-list-item"> 80/20 bronze provides a bright and vibrant tone </span></li><li><span class="a-list-item"> Gauge (medium): .013， .017， .026， .035， .045， .056 </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/516MHB%2BZA%2BL.jpg" noproxy>