IIJmio Coupon Switch (mioPON) enables you to switch on and off your coupon. "Coupon" means the max data volume that you can send and receive at max speed. While "Coupon" remains, you can control your data rate at the high or low speed with this application. To purchase coupon or check the detail of coupon volume, please visit IIJmio Web site (. Jp/service/setup/hdd/ ).