Trevor - how did you manage to go to page 1290 of their catalog? I can't find any mention of their catalog on their site and google isn't too helpful, either. You do look close. The box is puzzling, though, since you wouldn't go to the trouble of making such a nice box for something which was not an instrument (i.e., something which gets installed and not touched again). I do think these are filter related, though, because if you look at the circumferential holes they are not clear holes all the way through on any of the disks. The ones with a letter F in the number have a pink substance viewable through the holes and the two without an F have a grayish color visible through the holes. It is also interesting that the designation starts with 9 and there are nine disks. On Mon, May 29, 2017 at 11:42 PM, Trevor wrote: > RussellMc wrote on 30/05/2017 11:47: > > Theories so far are lapping disks or spinnerets. > > > http://www.trademe.co.nz/business-farming-industry/ > industrial/other/auction-1336533507.htm > > Looking at the HoffmanOnline.com catalog (p 1290), they're stainless > steel vent drains for a thermoelectric dehumidifier to allow accumulated > water to drain out the bottom of an enclosure. The UL-approved vent > drains also function as an air pressure equalizer, reducing the harmful > effects of temperature-induced vacuums that could pull water and > moisture into the enclosure. > > Maybe ... > > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .