Littelfuse® SAO020 SAO Type S Fuse Adapter, 20 A, For Use With TOO, TLO, SOO and SLO Series Plug Fuse

Designed to prevent installation of wrong size fuses, Type S Adapters (SAO series) screw into Edison-base fuse holders so they may accept Type S fuses. Once installed the adapters cannot be removed. To prevent shunting of open fuses or overfusing, and to reduce nuisance fuse opening, it is recommended that SAO adapters with properly rated SLO or SOO series fuses be installed in all Edison-base fuse holders.