Collet ER, according to standard DIN 6499, form B, type class 2, size ER 25. Brand Gurfer with reference ER25-2.
Also available: set of collets ER, DIN 6499 B CL2, size ER 25, Ø 2,0 - 16,0 mm per 1 mm, 15-piece, in plastic storage case (ref. ER25SET2).
For mounting tools with straight shank.