This is a stainless steel case for 7S26, NH35 and related movements.  It is speced out to be similar to Seiko's 02W0 case with the crown near 4 o'clock.  It has a 20mm lug width and a 39mm diameter.    Additionally, this listing comes with a crown, crystal gasket, and long crown stem to be cut to size for your appropriate movement and spacer.

This case uses a 30mm crystal and is compatible with a standard Seiko 5 caseback. 

Please note that this does NOT come with a movement, caseback, or end links.