In bongs and dab rigs, there is a feature called an "ice catcher" that lets the neck of the device be filled with ice cubes to cool smoke. This makes it easier to inhale more smoke or vapor and is easier on the throat.
An ice catcher is a point with indentations at the base of the neck on some bongs and dab rigs that allows the neck to be filled with ice. The purpose of an ice catcher is to use ice to cool the smoke or vapor you inhale, making it easier on your throat and allowing you to take in more air.
You can put as much or as little ice in the neck of your bong or dab rig as you like.To avoid damaging the glass, angle the device and allow the ice to slide in.
When smoking, some of the ice will melt, so ensure that the water level in the chamber is low enough to prevent the ice-melting water from flooding the bowl.