M42 Mount ! The lens optics are unmarked, no signs of fungus.
Vivitar 135mm 1:2.8 Auto Telephoto M42 lens
Vivitar 135mm F/2.8 Portrait Lens With Lens Caps - M42 Mount
Zoom Lens Vivitar AF MC Auto Focus 28-70 mm 3.5-4.5 Nikon AF Faulty #1
Vivitar close focusing auto zoom 35-105mm
Vivitar Auto Telephoto Lens - 135mm f/2.8 Prime Lens - Canon FD Mount
Vivitar Komine 135mm f/2.8 Auto Telephoto Lens with Case Mount Unknown
