Caldercraft Model Boat Fittings 8107DW 7mm Double block. Walnut.
Sold in packs of 10, these double blocks measure ((h) x (w) x (d)) 7mm x 3.8mm x 4.6mm and are available in walnut.
Equivalent manufacturers part number cross references:
Caldercraft 8107DW
Disar Models DM11004
Mantua 37070