The most common hallicrafters knob wrench is the Bristol Wrench. The xcelite number is 99-63. 4 flute 0.069 inch. The larger size is 99-66. 6 flute 0.096 inch. -- Rick Smedberg WA8YLZ P.O. Box 148 Custer, MI 49405 smedberg at t-one.net http://www.t-one.net/~smedberg Grid Square EN63vw