27,000 RPM Tie Clip (May, 1962)
POWER TIE CLIP by L. M. Cox Co., Santa Ana Calif., is an operating internal combustion engine. The motor has a displacement of only .01 cubic inch, with a piston hardly larger than the head of a pin. It can fly a very small model airplane, however. As a tie clip it is decorative but non-operable unless you carry with you the 1-1/2-volt battery to attach to its glow head and a drop or two of fuel. Rotary valve engine does 27,000 rpm. Gift-packed, with manual, $8.