This used Bell System 139-B test set is a vintage piece of telecom equipment. Free shipping is available for this item. Originally designed for telephone line testing, it may now appeal to collectors, history enthusiasts, or professionals in the telecommunications field seeking a historic tool. The item's condition is noted as used, which is typical for vintage hardware. Its practical value lies in its historical significance and potential use as a collectible display piece or educational artifact. As with many older technical items, specific functional details or accessories may vary; check the listing for full details on its current state and included components before purchasing. Vintage Bell System Number 139-B Test Set. Condition: Used. Listed at 17.00 USD. It could also be used to create a talk circuit for two technicians to converse while testing lines.