I can't say anything but good, as long as you don't go outside their voltag= e limits, and don't use them on equipment whose ground is different than yo= ur PC. There are optically isolated USB interfaces available. --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .