My son had one of these for Christmas from his grandparents and loves it! I bought him these refills but to be honest they don't go missing as they are quite large. Although we tell him not to aim it at anyone they are pretty safe should an accident occur.
Cheap and everything but the fins is hard-wearing. However the fins are quite weak and easy to accidentally grab so worth getting some more for when they break or if you just think three shots is too few.
Quick, efficient service, item delivered earlier than advised, pleasantly surprised. Exactly as expected and required, good description given for the model of cross bow we have. My son is really pleased.