We are told that these were made in WWII (most are dated 1945). They were used to attach bombs to each other so they would fall in a cluster. This was used primarily against German submarines. The basic idea was that instead of having to come up with a bigger 1,000 lb. bomb, you could tether (5) 200 lb. bombs together. These "bomb tethers" are packed 200 pieces per original wooden crate. You can buy them individually or by the crate. - Bomb Tethers///brand_for_product_detail=US Military,close_out=Yes,companydescription=US Military - Made in the USA,condition=New,condition_google=new,cost=0.250000,countrymade=Made in the USA,country_flag=no_selection,featured=0,flag=no_selection,identifier_exists=0,instock=in stock,is_recurring=0,madeinusa=1,manufacture_country=United States,product_image_size=Default,product_page_type=Default,square_product_image=https://square-production.s3.amazonaws.com/files/15aaf477060cc4c826cfa27e9f5b4f7dd6fff999/original.jpeg,store_price=1.500000,sw_featured=No,sync_update_msg=Modified in Magento by harryepstein on 06/11/2017,url_path=bomb-tethers