I bought it at a big sale with the Princo PR001B-RGWT. Unfortunately, I have to throw away the RGWT, but SSBK is still smart. It works properly with its normal battery except the special battery. Then, I replaced it by the spared special battery attached to parcel. Finally, it works properly by two types of battery. I bought two Princo watches. One works properly, but the other one does not work properly. It's difficult to write reviews whether it is good or not.