WINDOW BLOCK AND TACKLE SASH BALANCE

Hello there. Based on the nylon attachments, this looks like an S395-15 Channel Balance. For any replacement channel balance you also have to choose a stamp option, which designates the strength of the balances. Your old balance's stamp of 1490 is from a rating system we do not use. To know what stamp to select, weigh the window sash your balances support. You can then match that exact weight with one of the weight ranges listed alongside each stamp option under the product description on the S395-15 shop page. Let me know if you have further questions.