Ceramic Aquarium Shrimp Shelter Small 3 Hole Pipe Stack  Part # ST163
 
Size Approx  8cm L x  6 cm W x 4.5 cm H   |   3" L x  2.5" W x  2.25" H 
1 - Entrance Holes @ 4 cm x 3.25 cm   |   1.5" x  1.25"   
Provides refuge and protection from predators
Can provide substrate for fine algae or bio-film
Seclusion for molting / female with eggs