The four photos are for an OverDrive PolyPro 3, made by Classic Accessories. Designed for a molded fiberglass trailer like a Burro, Casita, Oliver, Escape, or Scamp compact trailer. Specs on their website show for 11 to 13' trailer bodies, part number: 80-295-153101-RT. List at $191, appears never used for $60 total.
If the ad is up, they're available, so inquiries asking "if available" and or without a phone number will be ignored. I don't text much and with limited time, emails won't be answered without a contact number. So, a phone call is best for a prompt and accurate response. John at 53ZERO-277-80NINE8