Obverse Design "4TH CO. CAC" (4th Company Coast Artillery Corps) curves along the top. The center has an ornament of two arrows pointing at a center circle. "FORT GRANT." curves along the bottom. There is a circle of small beads near the rim.
Reverse Design "GOOD FOR" curves along the top. Large "5¢" is in the center with a vertical cent sign. "IN TRADE" curves along the bottom. There is a circle of small beads near the rim.
Metal Aluminum. Weight Unknown. Size and Shape Round, 24 mm in diameter.
Dates Issued Sometime between 1914 and 1924.
Issuer Fort Grant, a subpost of Fort Amador, and built on canal fill and three former islands in Panama Bay. Fort Amador opened in 1913 as Fort Grant, and was renamed for Panama's first President. Ex-President Amador died on May 2, 1909, just a few months after the end of his term in office. The Fort Grant name was then used to refer to the causeway and three fortified islands adjacent to Fort Amador. Flamenco Island was the last and largest of the three island and the site of a major coast artillery battery. Over time the causeway islands ceased being referred to as Fort Grant.
Mintage Unknown.
Rarity Very Rare. Manufacturer Unknown. Source Cunningham's CZ210.
Varieties This is the only known variety. There is a dot inside the bottom of the "5" on the reverse.
Function Perhaps a post exchange token.
Population Count Two specimens in collector hands are known to me. I do not know of any recent sales.
Notes

On the 14th of August, 1901 this unit was constituted in the Regular Army as the 116th Company, Coast Artillery, Artillery Corps. It was organized on August 17th at Fort Screvin, Georgia, where it was stationed until July, 1916. At that time the unit was redesignated the 4th Co. CAC and stationed at Fort Grant. On June 30th, 1922 the unit was redesigned to its original name as the 116th Co. CAC. On July 1, 1924 it was reorganized and redesignated as Battery "A", 65th Coast Artillery.

Form this we see that the token must have been issued between 1916 and 1922.