As of the most recent 10-K, Visser has the following remaining warrants:
Shares/Exercise Price/Expiration
21,317,094 $ 0.16 June 1, 2017
10,540,750 $ 0.17 July 2, 2017
10,066,809 $ 0.07 March 10, 2026
They have no obligation to exercise these warrants but they will expire.