The is the locking washer for the 1/2" shaper spindle on the Atlas/Craftsman wood shapers. Without the tab on the washer the nut could work loose and then stand back!!! These do wear out in time and have to be replaced. Shipping on this item is free via USPS or UPS. I do combine shipping wherever possible. I do ship internationally. Just email me and I will quote shipping to your country.This washer will also work on the Walker Turner 700 series model 99PM2313 shaper, the Yates shapers.