#0 x 3/8" Phillips Stainless Steel Screws Qty 50
Used with 3d printed washers or with thick washers ( NOT Included ) to secure Kato Track to the modules from underneath.
STL File for 3d printable washers available for free download.
https://klawndyke.com/catalog/index.php?main_page=product_info&cPath=4&products_id=40