Intermatic K4221C 120-Volt Stem and Swivel Photo Control (2 Pack)

In this review of the Intermatic K4221C 120-Volt Stem and Swivel Mount Photo Control, the bottom line is simple: this two-pack is for installers and homeowners who want a straightforward, adjustable dusk-to-dawn sensor that replaces or upgrades standard stem-mounted controls. The single biggest reason to buy is the adjustable light level slide and swivel stem, which let you fine-tune sensitivity and aim the sensor without rewiring. The package also includes a washer gasket and locking nut, so users get what they need for a clean stem installation right out of the box.

Key Features

• Stem and swivel mount: The swivel on the 1/2-Inch-14 threaded stem allows precise aiming of the photocell to reduce false triggering from stray light.
• Light level slide adjustment: The built-in adjustment lets installers set the turn-on and turn-off threshold for dusk-to-dawn control to match local light conditions.
• Complete mounting hardware: Each unit ships with a washer gasket and locking nut so the sensor seals and secures to panel cutouts without extra parts.
• Compact footprint: Measuring 1 9/16' wide by 5 1/2' long, the body fits into common enclosures and fixture stems where space is limited.
• Safety listings: The K4221C is both UL and CSA listed, providing reassurance for commercial and residential electrical compliance.

Who It's For

The K4221C is aimed at electricians, maintenance crews, and handy homeowners who need a reliable replacement for existing stem-mounted photo controls or want an adjustable sensor for outdoor lighting, signage, or security lights. Its swivel mount and light level slide make it especially useful where light sources or reflections can otherwise cause premature switching.

Those who should look elsewhere include buyers who require multi-voltage models beyond 120V or integrated smart controls. If you need wireless scheduling, networked dimming, or a fully sealed industrial enclosure, a different class of photocontrol would be more appropriate.

Pros & Cons

Pros

• Easy installation with included washer gasket and locking nut, reducing time on site.
• Good functionality from the light level slide and swivel stem for precise alignment.
• Quality feel and value for money as a two-pack replacement option for hard-wired units.
• UL and CSA listing supports accepted safety standards for many installations.

Cons

• Durability reports are mixed among users, so long-term lifespan can vary by environment.
• Limited to stem-mount form factor and 120-volt single-voltage models in this listing.

Specifications

Product	Intermatic K4221C Stem Mount Photo Control (2 pack)
Voltage	120-Volt single-volt model
Mount	1/2-Inch-14 threaded stem with swivel
Adjustment	Light level slide
Included hardware	Washer gasket and locking nut per unit
Dimensions	1 9/16' wide x 5 1/2' long
Listings	UL and CSA listed

Our Verdict

The Intermatic K4221C is a practical, value-minded choice for anyone replacing a stem-mounted photocontrol or installing a basic dusk-to-dawn sensor. Its adjustable light level and swivel stem offer real installation flexibility, and the included gasket and nut simplify mounting. While some users report mixed longevity, the product's functionality, safety listings, and two-per-pack value make it a solid pick for standard outdoor lighting needs.

Frequently Asked Questions

Is this a direct replacement for hard-wired stem photocells?
Yes, customers report it works as a direct replacement for standard hard-wired stem-mounted photo controls of the same thread and mounting style.

Does it include the mounting hardware needed?
Yes, each photo control ships with a washer gasket and locking nut to secure and seal the stem in typical panel and fixture cutouts.

Can I adjust when the sensor turns lights on?
Yes, the unit has a light level slide adjustment to set the turn-on and turn-off thresholds for local conditions.