I'd describe this as a 'skiing' machine but don't know real name. You slide your feet (in opposite directions) along the curved rails while moving the arms. In good condition EXCEPT the rubber parts under the foot rests have mostly disintegrated so your feet are not stable when using. The rubber parts therefore need replacing so perhaps a clever person could remove the screws on the plates under the foot rests to do so. I've included a photo which shows some of the remaining rubber parts (yellowy bits just sticking out behind the plates).
The arms can be moved down for storage purposes, as shown in one of the photos.
Approximate size in centimetres: length 152, width 65, height (when arms down) 30.
Please state when you are able to collect in your reply, but not mornings. I'll reply to you in a couple of days. Thanks.