Tibetan hand or finger cymbals are not uncommon but genuinely old examples with a tone as refined and pure as this pair are rare.
This fine pair cast in bell metal and connected by a leather strap would have been used in connection with the lower Tantras and with offerings to minor deities in Bardo rituals. They were not used in temple orchestras however (Henss, 2020, p. 306).
Ting-shags are mentioned in 9th-century Dunhuang manuscripts and have been known in Tibet since the 13th century. Most probably, similar forms in early India influenced the ting-shags of Tibet.
The pair here have signs of good age and again, have a rare clarity of sound.
References
Henss, M., Buddhist Ritual Art of Tibet: A Handbook on Ceremonial Objects and Ritual Furnishings in the Tibetan Temple, Arnoldsche, 2020.