THIS IS A SANDVIK COROMANT MODEL A393.22-100 COLLET CHUCK. THE HOLDER TYPE IS CAT 50. IT FEATURES A BODY DIAMETER OF 2.75 INCHES AND A BORE DIAMETER OF 1 INCH. THE OVERALL LENGTH IS 7-1/4 INCHES, OR 8-1/4 INCHES WITH THE BUTTON. THE PROJECTION MEASUREMENT IS 3 INCHES. THE PART NUMBER IS A393.22-100.