The Littelfuse ACS 3AG Panel Mount Fuse holder is designed to eliminate the possibility of electrical shock, as defined in IEC standards 65 and 257. Shock-Safe fuse holders feature a low profile body, finger grip knob and anti-tease feature that eliminates circuit interruption when knob is accidentally depressed. 20A Maximum Amp Rating. For more than 75 years, Littelfuse has been the Circuit Protection manufacturer to achieve the automotive industrys most significant accomplishments, beginning in 1927 by inventing electronic circuit protection technology with the first small fast-acting protective fuse. Today, Littelfuse partners with every major automotive and heavy-duty OEM. That is why more than 95% of domestic and 70% of foreign new vehicles contain Littelfuse fuses. Littelfuse has introduced every new fuse in the industry for the past three decades, starting with the ATO blade fuse. Littelfuse holds more than 130 patents on circuit protection devices, more than all the other fuse manufacturers in the world combined. Other fuse manufacturers are licensed by Littelfuse to utilize its product designs and trademarks.