I recently acquired a Vivitar 35-105mm f/3.5 lens. It has a close focusing option. The lens focuses down to 4ft normally (around 2ft @ 85mm with close focusing, maximum focal length with close focusing). The lens is 4″ in length at infinity. It is an extremely heavy lens taking a 72mm filter (I would guess about 20-24oz, deffinitely my heaviest lens). According to the serial number (37xxxxxx) it was made by Tokina. (according to the box diagram) Optically it appears to be composed of 14 elements in 8 groups and is multicoated.
The lens seems to handle okay optically. I haven’t had that much of a chance to test it, but I ran a roll of film through the OM-2 that I acquired with about half the shots on the roll with this lens at different focal lengths and aperatures. On the whole though I would say I dislike the lens. It is HUGE for its focal length and aperature. You’d be better off carrying a 35-70mm f/3.5 and a 100mm f/2.8 lens to cover approximately the same focal lengths and you’d still come off with a lighter package. I paid $35 for the lens, a Vivitar 2x teleconverter and an OM-2 off craigslist.