Rapid-Mini-Dynamics-Trolley-Set-Rapid-P10516-p-A-set-of-two-trolleys-that-are-designed-for-use-in-the-demonstration-of-&-experimentation-in-dynamics-Each-trolley-features-a-recessed-rectangular-well-for-accommodating-extra-weights-increasing-the-effective-weight-of-the-trolley-p-Rapid-Mini-Dynamics-Trolley-Set-Plastic-132-x-55mm