This is an individual stack of 50 lbs. of weight for exclusive use with fitness equipment and machines from Inflight Fitness. Suitable for use with the fitness training units from Inflight Fitness-the CT line of machines, the Vanguard and the Liberator. This stack will increase the weight held by the device, maximizing exercise potential for users. Please note, this is a 50 lb. Heavy Weight Stack only. All CT machines, the Liberator Training System and Vanguard Training System are available separately. NOT designed to be used as a free weight or a free weight accessory. This stack is not intended to be used with nor fit on the various benches or dumbbell racks. Compatible with units that come with 150 lbs. or 200 lbs. standard. Weight stacks can be upgraded to a maximum of 300 lbs. Solid, durable and rugged, the weights are made of cast steel and are near-impossible to damage. Easy to clean, needing only a damp, warm cloth and some mild soap.