Some slide-out beds or gouchos use wood bed slides. Typically 3 or 4 were used on each bed.
Our high quality bed slides are 32" long solid maple and when fully extended are 55-1/2" long. They are 1-3/4" high and each slide is 1" wide, creating a 2" overall width. One half is screwed to the plywood platform and one half is screwed down to the base framing.
Note: slides typically arrive with a steel brad in one end that is used to prevent the slides from separating during shipping. It should be removed before installation.