Although Timex no longer makes HRM watches, you can still find them for sale on the USA eBay and some sellers will ship to South America. For example >>>
https://www.ebay.com/itm/19433220208...1&isGTR=1#shId
You will need to replace the battery (CR2016 or CR2025), since these are very old stock, and the original batteries in these watches are dead.