Green metallic Mongoose Switchback 21 speed mountain bike.
Frame size 21.5
Index shifting, quick release wheels
It is missing the rear fender.
From the number stamped on the frame, Gemini estimates it was manufactured September 1994 but could be the 1994 or 1995 model.
It has been a work in progress for the past two years, with new tubes and flat protection liners. I use it in the city and it rides great, but I think it is a little large for me for mountain biking. Some spots of rust, all superficial as far as I can tell. The rims are pretty straight, the frame is straight, but 32 years old it needs tweaks now and then. Tires are 26x1.90 and hold air fine but are getting old. Frame is CR-MO. Components are mostly Shimano.