It is possible that you have selected a lifting gear that was not originally designed by CERTEX. It is also possible that the existing lifting device no longer functions properly for various reasons, e.g. due to damaged parts, defects, repairs that cannot be carried out, etc. When defective parts can no longer be repaired, rebuilding from a sample may be cheaper than buying a new part. Sometimes a rebuild can be cheaper, possibly even faster and thus more reasonable than a more costly repair.