Printed in reef safe black ABS plastic. 2" Will hold up to a 2" round disk. Hole in the center for frag plugs. Secure the plug stem underneath with several loops of a rubber band and the plug will stay secure in the box. 4" box has a solid bottom. Removeable lid included with each. These are a little shorter and slightly thinner walls compared to my standard baskets and only available in the two sizes and hole pattern pictured.
Dimensions as follows:
2" (51mm) diameter inside and 1.5" (38mm) tall. Holes .2" (5mm)
4.2" (108mm) diameter inside and 1.5" (38mm) tall. Holes .2" (5mm)