Instruction Manual for the Tenma 72-320, 20 Mhz., Dual Channel Oscilloscope. The Tenma Scope was manufactured under license from Sperry as a copy of the AW Sperry 620C. Several other companies were also licensed to make a copy of the Sperry 620C .The ones I know about are the Tenma 72-720, Elenco MO-1251,Eico 482, JDR 2000, Speco FS-4320, and Brunelle 2988. This manual should be good for any of those oscilloscopes. The manual for sale is a hi quality copy, not the original. It is complete including schematics . Shipping $2.50, First Class Postage USA ONLY. Payment by Pay Pal or Money Order. NO returns or refunds