Torx Screw 2.5 mm T8 ( Pack of 100 Pcs) 12MM APMT CUTTER There are many Chinese brands

There are many Chinese brands also making the same inserts so you can just check the description of the size from other brands to fix this insert

SDMT-1204-80-27-6T  -Suitable Holder FMA27

ER collet sizes range from ER8 to ER50

so you can just check the descriptions of sizes from other brands to fix this insert

Insert it into this

Torx Screw 2.5 mm T8 ( Pack of 100 Pcs) 12MM APMT CUTTER There are many Chinese brandsThe hardened Star Torx screws for milling cutters offered are screws that come with precision design and construction standards. These Torx screws are hardened to 50 55 HRC for wear resistance. These Torx screws are primarily used in indexable tools, including boring bars, insert cutters, and milling cutters. They are precision screws designed to improve the grip of carbide inserts with pockets. One packet contains 100 pieces; choose the length.