HO Weight Upgrade Kits
| Manufacturer | For Car Kits | For RTR Cars |
| Athearn | Box Cars | |
| Cabooses | ||
| Flat Cars | ||
| Gondolas | ||
| Hopper Cars | ||
| Intermodal | ||
| Passenger Cars | Passenger Cars | |
| Reefers | ||
| Stock Cars | ||
| Tank Cars | ||
| Accurail® | Box Cars | |
| Flat Cars / Auto Racks | ||
| Gondolas | ||
| Hoppers | ||
| Intermodal | ||
| Reefers | ||
| Stock Cars | ||
| AMB | Cabooses | |
| Bowser | Flat Cars | |
| Gondolas | ||
| Hoppers | ||
| Stock Cars | ||
| Branchline | Box Cars | |
| Passenger Cars | ||
| Eel River Models | Box Cars | |
| Exact Rail | Hoppers | |
| IHC | Passenger Cars | |
| Intermountain | Box Cars | |
| Flat Cars | ||
| Gondolas | ||
| Hoppers | ||
| Reefers | ||
| Tank Cars | ||
| Rivarossi | Passenger Cars | |
| ScaleTrains | Box Cars | |
| Walthers Trainline | Flat Cars | |