The order forms part of a contract secured by GD last September for the delivery of 589 AJAX platforms to the UK Army.
Under the latest contract, the company will supply LCD 3.3 detectors designed to provide crew members with early warning of any chemical warfare attack.
Worth almost £6m, the contract is the result of a two-year development programme, which involved the modification of the detectors’ special mounting system to meet the vehicle’s specific requirements.
Smiths Detection vice-president EMEA Tony Tielen said: "This major military programme provides Smiths Detection with a valuable reference system for vehicle integration.
"The importance of AJAX was recognised by releasing it into full production as a front-line vehicle for UK land forces.
"With continuing news of chemical weapons being used by terrorist groups, Smiths Detection’s LCD 3.3 will play a critical role in keeping troops safe. We look forward to working with General Dynamics UK on the delivery of this vital programme."
Formerly known as Scout, the AJAX project represents the future of armoured fighting vehicles for the UK Army. It will provide enhanced protection, as well as survivability, reliability and mobility, with an all-weather intelligence, surveillance, target acquisition, and recognition capability.
Operational in combined-arms and multinational situations across a wide range of operating environments, the AJAX variants are expected to enable the army to conduct sustained, expeditionary, full-spectrum and network-enabled operations with a reduced logistics footprint.
Under the UK Ministry of Defence programme, these military vehicles will be delivered from 2017 to 2024.