Perhaps more
link interestingly the bezel uses a black-colored and Dia-Shield-coated stainless steel insert. While many
link other brands and even Seiko often opt for inexpensive aluminum or somewhat more costly ceramic inserts the SPB sports
link steel. I've seen reports quoting other materials but have double triple even checked with Seiko U.S. and Seiko Japan with both confirming the bezel insert is stainless steel.