A Ghost telemetry link that speeds the development of your upgradeable Fusion Rifles. Lasts 30 minutes.
― In-game description

Fusion Rifle Telemetry is a consumable that increases the experience gained towards fusion rifles for 30 minutes.

Prior to Destiny: The Taken King, they could be purchased from Xûr or from dismantling upgraded legendary fusion rifles. After The Taken King, they were replaced by Special Telemetry.