Sonic sunglasses

The sonic sunglasses were a device the Twelfth Doctor used to replace his sonic screwdriver after he abandoned it. They were worn as normal, black sunglasses with no visible difference to non-sonic versions. He used them to recall the TARDIS after it had been dispersed by the HADS "dispersal" function. He hoped they weren't scratched. (TV: The Witch's Familiar)

He wore them as regular sunglasses during the 3 week party when he played his guitar. He called his glasses a "wearable technology". (TV: The Magician's Apprentice / The Witch's Familiar)