Silencers are used to, as the word implies, reduce or mute the sound during firing. Silencers need to be attached on the end of the barrel. All our silencers can easily be attached to the barrel. Please note that silencers/sound moderators are more effective on CO2/PCP airguns than on gas piston/spring powered airguns as it only suppresses the muzzle sound and not the mechanical sound.