功能

• It is a product from the vacuum tube era that old fans miss, but it is still in .
• Before the widespread of printed circuit boards, it was a typical style to assemble resistors and condensers in an orderly manner, draw out cladding wires, and connect them to vacuum tube sockets.
• Even in the age of transistors, it has been d to construct experimental circuits for beginners beca of its large structure and easy soldering.