Tridacna clams utilized special byssal threads to anchor themselves to rocks and substrate. When placed directly in the substrate of your aquarium, as is typical with tridacna clams, the byssal threads meander through the sand and wind up attaching to the bottom glass panel. This can be problematic if you ever need to move the clam because damaging these byssal threads can be very stressful. 

Brightwell Aquatics Clam Hammock is a clever solution that provides a secure foundation for your clam.  The specially shaped clam holder cups the bottom of the clam and will discreetly blend in with your natural substrate in the aquarium. After some time, the byssal thread will attach and you can now move your clam about without worry of damaging the byssal threads.  They will also not be as prone to getting knocked over before they attach, helping new clams acclimate successfully into your aquarium.