This is simply a naill tapping on a glass surface. Its a little fast tempo, irritating if you will. This was recorded at the open window institute sound booth in centurion, south africa.
Knocking tree times on a metalic door, close up, several takes. Note that a small electric rumble should be removed. France, 2018. Recorded with schoeps ab ortfrecorded on nagra ares bbwave stereo, 48khz, 24bits.