This is a Gridfinity Heat Set tool holder for these tools
https://www.amazon.com/ShineNow-Heat-set-Soldering-Install-Inserts/dp/B09VL41T7K/ref=sr_1_2_sspa?crid=188GNE8VJLXH6&keywords=heat%2Bset%2Binsert%2Btool&qid=1706644512&s=hi&sprefix=heat%2Bse%2Ctools%2C101&sr=1-2-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1
enjoy