Quite rare. This is a film technology read/write head for IBM mainframe environment dasd (direct access storage device, i.e. disk), In particular this is the head and terminal part of the arm of a 3380 disk storage unit. I got this one embedded in lucite in the occasion of my visit (maybe 1980) at the IBM plant in Mainz, Germany, where they used to build dasd units for mainframes.Maybe this is missing in your collection.As is, no warranty no return.Shipping to USA via registered airmai...l costs 22 US$. Other countries please ask.Paypal preferred, otherwise ask.BUYER TO PAY LOCAL TAX AND DUTIES IF ANY. Please be aware of this before bidding. US buyers please wait for the invoice before paying.