A non-lethal explosive device that produces a blinding flash and loud noise to disorient people. The loanword フラッシュバン is more common in everyday speech.
See also: フラッシュバン
The special forces threw in a stun grenade before entering.
The common loanword for 'flashbang', used in everyday and media contexts. 閃光発音筒 is a more formal, technical term.
Compound of 閃光 (flash of light), 発音 (sound emission), and 筒 (cylinder/tube), describing a device that emits light and sound.