US fin box with single 15mm Dia x 35mm long peg in the centre, to bridge to the deck for strength.
These are very similar to the Chinook Strongbox with peg, made from the same glass reinforced plastic, but are unbranded.
The slot is approx 9.5mm wide, making them ideal for use in boards intended to be used for Plate Head fittings.
Over all Dimensions
Length: 27 cm (slot is 10" Long)
Width: 2.5 cm
Depth: 6.5 cm