Obverse Design Legend curving above starts with a small five-point star and says "ADMIRAL . VERNON . AND SR CHALONER . OGLE". There is a line enclosing the legend. Along the bottom (in exergue) is an ornament that looks like a shell with one branch on the right and one on the left. A full length Vernon is on the left, his body oriented 1/2 to the right, and he is facing 3/4 right. His right hand is holding a baton and his left hand is pointing towards Ogle, and is almost touching Ogle. A full length Ogle is on the right, his body oriented 1/2 to the left and is facing left. His left hand is holding a baton and his right hand is pointing towards Vernon, and is almost touching Vernon. Vernon's arm is above Ogle's arm where they overlap. The medal has dentures along the edge.
Reverse Design Legend curving along the top says "TRUE BRITISH HEROES TOOK CARTAGENA". There is a line enclosing the legend. Along the bottom (in exergue) is the legend "APRIL 1741" (the "1" is weak and sometimes absent). The center is the attack on Cartagena. Two ships (with three masts each) are sailing left towards a fort in the foreground on the right. In the foreground on the right below the fort is a rowboat with two rowers and a passenger (Don Blas, but not named). There are waves in the water below the ships. Two forts in the middle are connected by a chain boom, behind which is a ship. There are waterlines above the chain boom and below the ship. Each fort has three buildings with a flag on the center building. To either side of the middle forts is a plain with a lot of grass lines. In the background the city of Cartagena is portrayed in a straight line across the medal. A flagstaff points to the "O" in "HEROES". A short tower at the right is pointing to the "K" in "TOOK". The coast line on the right is at "RU" (on the left it is not clear in my example). The medal has dentures along the edge.
Distinctions

Eight Admiral Vernon medals portray Vernon and Ogle on the obverse. Of those eight, seven have a Cartagena reverse. Of those seven only two have the obverse legend start with a star. Of those two, this one has a ship behind the chain boom and does not name Don Blas. The other variety has the rowboat behind the chain boom and names Don Blas.

Note: the reverse die appears to be identical to that of VN4-102.

Detail On Obverse of VN-4.125 Detail On Reverse of VN-4.125
Detail of VN-4.125
Note positions of Vernon and Ogle.
Detail of VN-4.125
Note the ship behind the chain boom with waterlines.
Metal Copper. Weight Unknown. Size and Shape Round, 37.5 mm in diameter.
Rarity Common. Designer or Issuer Unknown. Other Catalog Numbers Betts Unlisted, McCormick-Goodhart #229.
Notes