Full name, Phase shifter. Generally more subtle than a flanger, but sounds like space-age swooshes. It is often used on the Rhodes electric piano and, of course, by guitarists such as Brian May (Queen) and Eddie Van Halen (Van Halen). 

The Efektor PH3605 Phaser provides three types of sound:

Single phase:

• Smooth phase effect, ideal for a clean tone. Less dramatic sweep.

Dual phase: 

• Warm, thick phase sound that works very well with distorted guitar tones. Ideal for many instruments such as guitar, bass, keyboards, and vocals.

Multi-phase:

• More intense effect. Offers more than a standard oscillation effect.

Key features:

• Three modulation models in each unit.
• A/B comparison buttons.
• BPM sync.
• Mono or stereo mode.

System requirements

Mac

• Mac OS X 10.7 or later (Intel/M1 Apple Silicon compatible) (64-bit only)
• Core 2 Duo or higher (latest Intel i3 recommended)
• Minimum 4 GB RAM
• VST, VST3, or Audio Unit compatible host/DAW

Windows

• Windows Vista or later (64-bit only)
• Core 2 Duo or AMD Phenom II X4 or higher (latest version of Intel i3, AMD A4 or higher recommended)
• Minimum 4 GB RAM
• VST or VST3 compatible host/DAW

Important notes:

• Pro Tools 11 or later is required for the AAX format
• Reason 7.1 or later is required for the rack extension format
• A host/sequencer compatible with VST, VST3, AU, or AAX is required to run this software.