Supposedly the "rights are not transferable. Each right give the right to buy 0.48 units at $2.50. Rights said to expire after Feb 6.
Your broker may or may not charge you to exercise, and if the broker charges, it will probably be more than the charge for a commission.
The effect is to dilute the value of existing shares, and to assess holders to send more money. My experience with companies that do this is not good. However since the majority of the units are held by two people, maybe that is different? It's not good for the small holders generally IMHO. This has not been a good investment.
Exercise price is $2.55, not $2.50. Trading spot on right now. They need the funding since the partnership now processes and markets the nuts, rather than selling them to third parties "wet in shell". Obviously much greater cost burden, but potentially better market pricing. The "Mauna Loa" brand recongnition is well-established, but I'l bet it will take a lot of marketing effort (G&A expenses) to fully develop the "Royal Hawaiian" name. Would be curious on their store-branded (Costco, Trader Joe's, etc.) customer base. The problem here is lack of consistent cash flow and distributions to the partners. A much more aggresive investment than it used to be, but potentially higher growth if they succeed in building the brand.