Marty Mcfly Casio CA-50, Common to popular belief the CA-50 was the original Casio worn by Marty Mcfly, before he wore the CA-53 in the later scenes! This is mine I sourced
Casio CA-50 Calculator Watch Module 437 Back to the Future - Etsy 日本
2023年最新】CA-50 CASIOの人気アイテム - メルカリ
Casio CA-50 & CA-53w] Marty's Casio vs. the one still sold to this day. : r/Watches