<P> Invented at the same time as the crown cork, it is the original "bar blade". But as well as being portable it also comes as a fixed device to be attached to vertical surfaces, often with a tray to catch the bottle tops . It does not open wine bottles . It is class 2 fulcrum type . </P> <P> A simple opener is a piece of metal with a rectangular or rounded opening in one end and a solid handle large enough to be gripped between the thumb and forefingers on the other . The opening contains a lip that is placed under the edge of the bottle top, pulling it off when upward force is applied to the handle end of the opener . This type of opener is small and durable, so it is frequently used as a key fob . </P> <P> The speed opener is a flat blade of steel approximately 4 cm wide and 16 cm long with a thumb hole at one end and a letterbox cut at the other to remove the crown seals from a bottle . They go under the names' Speed Opener',' Popper',' Mamba',' Bar Key', and most popularly' Bar Blade' . The thumb hole may be used to pull bottles out of ice, by placing the hole over the neck of the bottle, then lifting it . The speed opener is widely used by professional bartenders in Canada, the United States, and the UK . Carried in the pocket or against the body or on a zip string, it is both convenient and fast for the modern bartender . It is advantageous in that it is easy to open several bottles in rapid succession, and with more flair than other types of bottle opener . Consequently,' bar blading' is often part of bar flair routines . </P> <P> Works the same as the lever variation, except that it is attached to the wall, to allow for simpler bottle - opening, which can be done with one hand . The bottle cap can fall into a bottle cap catcher mounted below the opener, or you can retrieve it after removal from the bottle . </P>

What is the hole in a bottle opener for