This document specifies technical characteristics and strength requirements for fork arm extensions and telescopic fork arms (as defined in ISO 5053-2) for industrial trucks (as defined in ISO 5053-1). It applies to fork arm extensions and telescopic fork arms that are designed for use on industrial trucks that have fork arm carriers and, in the case of fork arm extensions, fork arms that conform to ISO 2330. This document does not apply to integral transverse telescopic fork devices or scissor-action reach devices.