SET of 3 mounted ACHROMATS (2 negative, 1 positive)

• Description: SET OF 3x ACHROMAT LENSES (seem to belong to laser project). Set comprises 3 lenses only (I have 2 sets available, that's why you see 6 lenses in pictures). They are described as follows:
  • Mounted 9mm lens NEGATIVE achromat lens (with holes for easy screwing with appropiate lens removing tool). This mounted lens is then screwed in a brassed sleeve (focal length unknown, seems a bit less powerful powerful effect than 11,5mm). Sleeve details: 17,80mm diameter / 16mm length / M16 inner thread size / M2 locking allen screw (included). 
  • Mounted 11,5mm lens NEGATIVE achromat lens (with holes for easy screwing with appropiate lens removing tool). This mounted lens is then screwed in a brassed sleeve (focal length unknown, seems more powerful effect than 9mm). Sleeve details: same as above.
  • Mounted 13,5mm lens POSITIVE (not sure if achromat lens, it seems two plano-convex lenses confronted in their convex side so that the "plano" side comes out at each side). No brassed sleeve.
• Everything works smooth (the screwed lens screws easily up and down the sleeve and the locking screws work properly). Lenses are clean overall. 
• Remember "negative" lens means "barlow" effect in the optical train and "positive" the contrary.
• Issues: some normal usage marks.