These three came out of a Bendix BC-640 WWII radio transmitter cabinet used at both U.S. and R.A.F. bases in England to contact allied aircraft over the continent. The large ones are stamped 8000 (ohm symbol) at one end and CHD at the other. The center body is coated with porcelain with a cobalt blue glaze on the outside, unglazed inside. They measure 7 1/2" long. The smaller one is stamped 1500 (ohm symbol) and is 4 1/2" long. The glaze is dull but buffs up nicely with a well worn scotchbrite pad. I buffed one large one as an example. $17 for the set of three plus shipping. Check, money order or PayPal. Thanks!