The thumb is made of an inner layer of fiberglass and covered in imitation rubber skin painted Data's signature gold. The finger nail of the prop thumb flips up revealing a small button that activates a LED.
Worn by Brent Spiner as Lore in the Star Trek: TNG season four episode #177 “Brothers,” which aired the week of October 8, 1990. Data was summoned by Dr. Noonian Soong to his lab by homing circuitry so he could have an emotion chip installed. In the process Lore was inadvertently also summoned and he tricked Dr. Soong to install the chip in him. Lore opened his hinged thumb fingernail and pressed a small button to activate an emergency transporter to escape capture by the crew of the Enterprise and send him back to his Pakled ship. The thumb is made of an inner layer of fiberglass and covered in imitation rubber skin painted Data’s signature gold. The fingernail of the prop thumb flips up revealing a small button that activates a LED. Propworx 50 Years of Star Trek Auction September 10, 2016, Lot 58 – Prop Store of London – Profiles In History Hollywood Auction 31 March 28, 2008, Lot 908
