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HotLok® Round 4" Rack Mount Grommet - Model #40002


Designed to seal 4"(102 mm) cable openings in new and existing server rack cutouts to block bypass airflow and maximize cooling system efficiency.

HotLok® Round Rack Mount Grommet, the latest patent-pending thermal management solution is the premium choice for your facility. Its revolutionary sealing technology greatly reduces costly bypass airflow, increasing usable cooling unit capacity, and ensuring maximized efficiency from HVAC equipment.


  • The Split feature of the HotLok Round Rack Mount Grommet allows product installation or removal without disturbing cables
  • The Grommets contain no loose or partially fastened parts, which can become separated or fall into the rack
  • The Grommets are impact resistant and durable
  • HBT Membrane Layer ensures maximum air containment
  • HotLok products are compliant with directive 2002/95/EC of the European Parliament and the Council on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electric Equipment (RoHS)
  • The Grommet features a membrane support structure


  • Supports increasing cabinet density
  • Increases existing cooling unit capacity
  • Reduces the need to purchase additional cooling units
  • Improves IT equipment reliability and extends equipment life
  • Simple snap in place, installation saves time and labor and requires no downtime
  • Round grommets enable hole saw installation
  • Most cost effective tool for cable separation and cable management while minimizing bypass airflow in the rack
  • Durable ABS frame and Hybrid Brush sealing surface can be used for years
  • Hybrid Brush Technology (HBT) provides the most effective air seal in the industry and avoids sagging bristles


Patented Sealing System

U.S. and International patented Hybrid Brush Technology (HBT) design using thermoplastic elastomer creating a more effective seal than any other grommet. Tear lines minimize leakage in unused areas of the grommet when only a small number of penetrants are being used.

U.S. and International patent pending: single-layer, opposing and interwoven filaments consisting of premium-grade nylon Type 6 ensuring flexibility and self-sealing recovery along with guaranteeing passage of 30 amp power connector.

Sealing Effectiveness

New, patented Hybrid Brush Technology (HBT) offers exceptional sealing and airflow management, unsurpassed by other leading brush products on the market today. Hybrid Brush Sealing Technology automatically seals around cables with no additional maintenance or monitoring required.

HBT is uniquely constructed to offer:

  • Flexible and highly efficient sealing membrane
  • Membrane supports bristles to reduce sagging and limit leakage
  • Multi-layered construction for increased sealing effectiveness
  • Color: Black

Grommet Frame

  • The frame is molded from durable PC/ABS
  • Finish: Black

Rack Mounting System

Four(4) integrated self-securing molded clips ensure grommet is firmly fastened to the rack.

HotLok® Round 4" Rack Mount Grommet


Dimensions and Cutting Requirements Inches Millimeters
Item No. 40002 - Overall size (diameter x height) 5.60" x .7" 142 x 18mm
Product height above the rack .40" 10mm
Maximum thickness of plate at rack install location .0625" 1.6mm
Hole cut required for installation 4.0 - 4.08" 101.6 - 103.6mm
Usable cable area 9.6 sq. inch 6194 sq. mm

Tools Required

  • Tool-less Installation if Proper Size Hole is Provided
  • Hole Saw Cutting Tool and File (as necessary)
  • Tape measure

Install Images

  1. Cut 4"/120mm hole in the rack top or side
  2. Place grommet half with male tabs into 4" hole
  3. Take grommet half with female tabs and lower into hole until the pins engage the male clips
Installation Guide - HotLok® Round 4" Rack Mount Grommet


Locate or cut with hole saw a 4" (up to 4.08") or 102mm (up to 103.6mm) diameter hole in the rack or enclosure. Ensure that any burrs are removed, however it is not necessary to dress the cutout when installing a HotLok Round Rack Mount Grommet. The grommet dresses the edge satisfying NFPA requirements.

  1. Test fit the HotLok Round Rack Mount Grommet in the rack hole by slipping the grommet around the cables, assembling the two halves of the grommet and placing in the 4“ hole. Ensure there is no binding and that the grommet flange rests on the inside of the hole all the way around. If there is any binding, remove the grommet and check the hole and the HotLok grommet for any damage or debris.
  2. After test fitting the HotLok Round Rack Mount Grommet and no binding is noticed, the grommet can be installed by firmly pressing on the top side of the grommet until the integrated clips snap in place. If the grommet does not snap into the hole, separate the two halves and place the male end into the hole around the cable. Then take the female end, put it into the hole at an angle, lower it until the pins start engaging with the male end. The two pieces should slide together with pressure applied at the joints.

Removing the HotLok Round 4" Rack Mount Grommet

If for any reason the HotLok grommet needs to be removed, this can be done by lifting the center of the grommet to separate the male and female pieces. Once these pieces are separated, the clips can be disengaged from the rack and the two halves of the grommet removed.

Contact your local Data Clean account manager for more information.

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