Thorlabs Aluminum Breadboards, various sizes available

Black anodized

0.5" or .75" thickness

1/4-20 holes 1" OC or M6 metric

Sizes available

12" x 17.5" x 0.5" Price $110.  M6

12" x 24" x 0.75" Price $175.  1/4-20

18" x 18" x 0.50" Price $170.  1/4-20