Normally the 3.5" sinks come with a basket. The basket is good for stopping water but does not filter small residues. These Chokeless (Anti-clogging) sink strainers were designed to be place on top of the existing basket. The anti-clogging features will filter the residues and allows water continue to flow. When the residues are filling up the sink strainer at the bottom, the top water outlet will still allow the water to flow. They are made of thermal plastic therefore they will not have the rusty problem as metal does.
Advantages
•Chokeless Design.
•Resistant to hot boiling water (Up to 120 deg c).