From - Tue Jun 29 14:59:18 1999 Based on UCB's Dummy Shutter drawings (HSIS212 and 214) and Paul's e-mail of 22 June, it would appear that: 1. The 'THICK' shutter (nominal .060") refers to shutter 'A' and defaults to OUT on launch and in override mode. 2. The 'THIN' shutter (nominal .015") refers to shutter 'B' and defaults to IN. To avoid confusion, I recommend that we label our attenuator disks as A and B accordingly and drop the THIN and THICK designations. gordon