Constructo has designed the Double (wooden) Block to be used in the construction of their model ships. These Blocks may also be used for various craft projects. FEATURES: Light tan colored square shaped wooden blocks with one hole. Blocks may be used in conjunction with brass rings, rigging thread (block & tackle) or decorations with ship accesssories. INCLUDES: One package of 3mm Double Wooden Blocks (approximately 20) COMMENTS: NOTE: Today"s model wooden blocks do not have sheaves, they are represented by a hole in the block. Blocks are given different names, depending on their shape, purpose or place aboard a ship. They are termed single, double, treble, four-fold according to the number of sheaves contained within the body. It wasn"t the weight of the object that denoted the number of sheaves needed, it was the power that had to be applied. ConstructoPart CNS80010