Hybrid pallets are predominately a pallet made up of mixed materials or even different grades of materials.
As an example, you may require hardwood boards with softwood bearers. Or even the other way around.
The reasons for choosing these hybrids are diverse but some of the benefits and examples are;
If transporting a truckload of empty hardwood pallets over a long distance, the vibration caused by no weight being on the pallets may mean that your pallets will arrive with nails having worked themselves out of the hardwood. What this means is that you then have to check every pallet for loose boards and re-nail them before using.
A solution to this is to use softwood bearers as the nails have a better grip.