Hi, I'm cleaning out a BUNCH of modules from HP 5061A/B. See listing on eBay below. More lots of other modules to follow in groups that will fit into flat rate boxes. If you have specific wants contact me off list! Cheers, Corby https://www.ebay.com/itm/HP5061A-5051B-A7-AC-amplifier-modules-eight-Freq uency-standard-Cesium-standard/323183182781