This is a wonderful timeless Black Speidel USA bubble perpetual calendar expansion wristwatch band made of high-quality stainless steel and has a gold tone trim. It is compatible with Speidel watches and can fit a wrist size of up to 6 inches without stretching. The band is 14mm wide and has a stretch bracelet design for a nice fit.

Age of this band unknown but most likely  anywhere from mid 70's through late 80's s and made in the United States