I aquired some surplus modules on some circuit bds.The part I am looking at are made by function modules it says made by fmi a subsidiary of intech.the part is called 551 multiplier,about1.5 by 1.5in,marked as follows onleft sidetop to bottom v+,com,v-,out,out balance, top on rite side,sj,xbal,x,y,ybal,z.I knowwhat your thinking,why bother,so much other stuff to play with.These boards were made with .001% parts as in high grade military test parts ,probly were used by nasa,or test fixtures,for unknown uses,One board says traction motor simulation on it.Some boards had the yse scratched off.I got these boards at computer surpluss store.The place is about 100yrds by 100 yrds,2 storys tall,so where ever this stuff came from ,this place has any thing ever used in elec from the 50's to present day.most of the boards have 2n2219,2n2222,2n918,747,ic and 1n918 diodes all these parts plus mil spec labled parts all have helped in my rf projects,I love using a part thatis exactly what is on the lable of the device,.1%resisters,oh well,I been sitting on this stuff for a couple of yrs now.No one so far has any Idea who fmi is or was.So if you guys out there can help great.I didnt have access to the net till recently,so I thought I would try here .Tnx TomNE6AO 73 email leathertom@muleady.com,My throat cancer is as of 3 days ago is in remission