An RTI filing has revealed that the Delhi Metro Rail Corporation spent Rs 11.7 million (mn) on 20 anti-smog guns deployed in the national capital. The Delhi Metro Rail Corporation is the state-owned urban transport operator and the expenditure covered procurement and installation of the devices. The disclosure names the number of units and the total outlay without giving operational performance data. The disclosure was provided after a request under the Right to Information Act and includes documentation of the transaction. The records show that 20 units were acquired for use at metro stations and adjacent premises as part of measures to address seasonal air pollution. The documents list the procurement cost and the locations of deployment but do not attach evaluation reports on air quality impact. The cost figure has been converted from the original reporting to reflect the amount in million for clarity. Anti-smog guns are one of several interventions used to address episodic pollution across the city. The purchase represents a unit cost of about Rs 585,000 per anti-smog gun, calculated from the total reported expenditure. The per unit figure may assist analysts and urban planners in comparing alternatives and assessing value for money without implying an endorsement of the technology. The RTI response therefore supplies a quantitative basis for scrutiny of environmental spending. The total figure does not reflect additional costs such as maintenance, power consumption or staff time required to operate the devices. The disclosure has added to public information on municipal responses to pollution and can inform further examination by civic groups and policy makers. The figures will be relevant to debates about the best deployment of limited public funds to improve air quality across the city. Officials have the data needed to evaluate results and to decide on any adjustments to strategy. Stakeholders can use the disclosed numbers to model costs and to recommend oversight measures where appropriate.