The Pro Sinktastic Strainer and Stopper is made of BPA free flexible thermoplastic that seals by water pressure. Keep the center stopper insert in when you want to hold water in the sink， remove it to allow water to drain through， leaving any debris caught in the strainer for disposal in the trash. Fits all sinks and disposers - just drop it in， no plumbing required. Fresh scent fragrance and anti-bacterial agent.