Ceramic Aquarium Shrimp Shelter - Small Tree Head Part # 11991-03
 
Size Approx  10cm L x  3 cm W x 4 cm H   |   4" L x  1-1/4" W x  1-1/2" H 
2 - End Entrances Holes @ 2.54 cm x 2.54 cm   |   1" x  1"   
2  - Side Entrance Holes  @  3 cm x 1 cm   |  1" x 1/2"
Provides refuge and protection from predators
Can provide substrate for fine algae or bio-film
Seclusion for molting / female with eggs