The Unknown device noticed yesterday on T-72 tanks and BMP-1 of Syrian army. Еhe device looks like a cylinder with sensors and it is likely to active protection system.

The  active protection system is a system  designed to prevent line-of-sight guided anti-tank missiles/projectiles from acquiring and/or destroying a target.

Externally, the new complex resembles the Russian Arena active protection system (APS) developed at Russia’s Kolomna-based Engineering Design Bureau. But in the complex are not visible launchers for defensive rocket is fired that detonates near the inbound threat, destroying it before it hits the vehicle.

Maybe it’s just optical sensor classifies the incoming threat for smoke grenade launcher systems.