Type 86 high gain, fast rise preamp for 580 series scopes. Very clean, appears to be complete with no damage. Normally, I'd test for functionality, but a 580 scope is one of the types I don't have. Comes from Poulter Labs at SRI; known for explosive propagation and high speed impact testing. All the test gear I've had from SRI was functional when I received it, so I'm confident this will be too. (However, I'm sure it will need to be calibrated after 40 years!) Free manual (pdf) is available from the TekWiki site.