Caldercraft Model Boat Fittings 8107DN 7mm Double block. Natural.
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 natural boxwood.
Equivalent manufacturers part number cross references:
Artesania AL8523
Billing Boats BF700
Caldercraft 8107DN
Corel AMNB117
Mantua 37071