Depending on the exact model, most 2000-era Midland pups were:
Tandem or tri-axle
Steel construction
15–30 ft box length
Air ride or spring suspension
Pintle hitch setup
Air brakes
Designed for gravel, asphalt, dirt, demolition, and aggregate hauling
Many Midland pup trailers were configured similarly to today’s:
XL3100 tri-axle gravel pups
XL2000 short-haul dump setups
End dump pups for tandem or tridem dump trucks