Pair of pistons (gas springs) for storage bed, complete with spare rings for attaching the piston to the lift mechanism. The 41.5cm measure indicates the distance between the centers of the holes or pressure heads. Check the strength of the pistons and select the ones that best suit your needs. For optimum operation better replace both pistons. To check the functioning of the gas springs you need to place the mattress on the base. Without the weight of the mattress, the mechanism will not close and you will feel stuck. Do not try the pistons by closing them by hand before fitting as they will not close. Old pistons can be closed by hand because they are unloaded (this is the same reason they can't keep the bed open). Power indicates the piston's ability to support a weight. Approximately 1 kg is equivalent to 9.8 N.