The TP Junior Trampoline is a design classic, having been invented by TP back in the 1960s. This trampoline is suitable for children as young as 12 months if your child is confident & starting to walk.. Because all the materials are thoroughly tested for a generation's use & extremes of weather this TP Junior Trampoline is suitable for both indoor & outdoor use, all year round.. The TP Junior Trampoline has a unique detachable handle with easy grip pad which allows easy storage under a bed or behind a sofa.