it's a TVC mount for 18mm rocket engine and for a 60mm airframe. 

You need M3 screws, 1.5mm metal rodeS and a 4mm cardan.

link for the cardan:

 (https://www.amazon.fr/sourcing-map-argent-diam%C3%A8tre-douille/dp/B00GWFC0L4/ref=sr_1_5?__mk_fr_FR=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=271ETWQB4IHSB&dib=eyJ2IjoiMSJ9.fKpPuPluVhkQjeMfcWtR5VPUrxzAHUvG5bjY3JrfWByCj-EQxYLN_QhZbBSIbq2OhZ7ETAzkH0PqFj5nxrqPkQKGFFHdFTQBqw4mcQQRfOSPF9w229ufPayQ2czfdD_eHWBWBt00fOCoa9dwcHQ0stmnRxXDc4g_6NEvFpdfE2YvUX64awuF8-rmoSq8PrWTQDg4WE0ooG6U67B5BSshFmWmVBGuk1oF1j1q23KBa-RwR9w2I5-4UY4XmT5-DQuzgMCBuEakj__jrrbQRBh8PedLyzlnRteuMh7oStdvYcM.DG_bSJUH0UVIw9FC9Uz3YN-k-TfbVmxXBS2q4Tvygm0&dib_tag=se&keywords=cardan+4mm&qid=1709300008&sprefix=cardan+4mm%2Caps%2C290&sr=8-5)