Brands Guides About
Middle Atlantic GK-4G 4-Inch Gland Grommet Kit — main product image
Middle Atlantic

Middle Atlantic GK-4G 4-Inch Gland Grommet Kit

★★★★★5.0 (1 reviews)

Four rubber grommets engineered to protect cables and seal 4-inch trade-size knockouts in any rack enclosure or equipment cabinet.

$68.00*
Check availability

*Price sourced from Amazon.com. Last updated:Jul 14, 2026.Price and availability are subject to change.

Affiliate Disclosure: Studio Supplies may earn a commission from qualifying purchases made through links on this page, at no additional cost to you. This helps support our editorial team.

Notice a mistake? Let Us Know

Overview

The Middle Atlantic GK-4G is a four-piece kit of 4-inch rubber gland grommets designed to finish cable entry points in rack enclosures and equipment cabinets. Each grommet snaps into a standard 4-inch trade-size knockout opening — the pre-cut circles found on the sides, tops, and bottoms of most professional rack cabinets — and provides a clean rubber border around cable bundles passing through. The functional benefit is twofold: the rubber edge protects cable jackets from the sharp metal edges of the knockout opening, and the grommet's presence gives the installation a finished, professional appearance versus the raw metal of an open hole.

These are the kind of parts that get overlooked in budget planning but noticed immediately in the finished installation. The rubber material is flexible enough to accommodate cable bundles of different diameters through the same opening, and it offers a meaningful reduction in dust ingress compared to an open knockout — useful in server rooms or AV equipment rooms where airborne particulates are a concern. Installation requires no tools: the grommet presses into the knockout and stays put. The same snap-in design means they're removable and reusable when enclosures get redeployed or recabled. One kit covers four openings, which aligns with the typical knockout count on a standard Middle Atlantic enclosure side panel.

Key Features

4in

Specifications

Size
4 inches
Material
Rubber
Compatibility
4-inch trade-size electrical knockouts
Quantity
4 pieces per kit
Installation
Tool-free snap-in

Pros & Cons

👍 Pros

  • Rubber construction flexes around cable bundles of varying diameters, accommodating changing cable densities without replacement
  • Standard 4-inch trade-size knockout fit provides broad compatibility across Middle Atlantic and most competing rack enclosure brands
  • Four-piece kit supplies enough grommets for a single cabinet's standard knockout count without requiring additional purchases
  • Snap-in design allows tool-free installation and removal, making them reusable across multiple enclosure deployments
  • Protects cable jackets from metal knockout edges that can abrade insulation under vibration or shifting

👎 Cons

  • Compatibility is strictly limited to 4-inch trade-size knockouts — enclosures with 2-inch, 3-inch, or non-standard opening sizes require separate grommet SKUs
  • Rubber material may degrade over time in high-heat rack environments where temperatures consistently exceed typical equipment ratings
  • No integrated cable tie-off or strain relief — cables remain free-floating through the grommet opening
  • Does not provide a positive IP-rated environmental seal; cable gaps within the 4-inch opening remain partially open
  • The four-piece quantity assumes one kit per standard cabinet — installations with more than four knockout openings require multiple kit purchases

Frequently Asked Questions

The GK-4G is designed to fit 4-inch trade-size electrical knockouts — the standard opening found in Middle Atlantic enclosures and most competing rack cabinet brands. If your enclosure uses 4-inch trade-size knockouts, these grommets are compatible.
Four individual grommets are included in the GK-4G kit. For a single enclosure with four knockout openings, one kit provides complete coverage.
Yes. The rubber gland grommet design allows multiple cables to pass through the 4-inch opening together. The flexible rubber material conforms around cable bundles of varying diameters while still providing edge protection and a cleaner appearance than an open knockout.
The rubber construction offers moderate dust sealing around cables passing through — better than an open knockout. They are not rated for full environmental sealing or IP-rated enclosure applications, but they meaningfully reduce airborne dust ingress in typical rack environments.
Yes. The rubber grommet snaps into the knockout opening and can be removed and reinstalled without tools. This makes them reusable when reconfiguring enclosures or redeploying cabinets.

Related Products