Giftworthy
Comes fully charged. 100% waterproof. There is only ONE 3 headed grinder. The packing list on the product page  lists "3 x 3 in 1 Grinding Heads", so I believed it came with 2 replacement heads, The marketing materials show you how to replace the head, however I am unable to find where to obtain them. Hopefully by the time these wear out in a year they will be available.
Rating: 4 stars