We have a 2019 Landmark Concord whose bed linear actuator died almost immediately after we bought it. Attached are the specs and parts information on it:
Manufacturer: P-TECH
Model #: LC65-144-12-1475
Stroke: 18 inches
Load: 400 pounds
Speed: 9 inches/sec
Duty: 2m/18m
I hope this helps. If you can't find this exact actuator, I know there are others available that will have similar specs.