This is Curaprox Swiss CPS 09 Prime Refill Interdental Brushes 8 Pieces Yellow.
Curaprox interdental brush tips help reduce your plastic waste! Why throw away the whole brush when only the tip needs replacing. With the unique Curaprox interdental system you can do just that. Each brush has been designed to last longer than standard interdental brushes offering flexibility when needed so you will be changing your brush far less. Make the switch today for a 100% clean and help to reduce your plastic waste.