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JE Berkowitz, LP is the premier high quality architectural glass fabricator in the United States. As an ISO 9001 certified company, we are committed to excellence and quality in the processing and distribution of glass products to our customers.

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  • 1-800-257-78272
  • One Gateway Boulevard, Pedricktown, New Jersey

JEB 3Seal HM+

JEB 3SEAL® HM + Warm-Edge Spacer

High-Performance, Warm-Edge Insulating Glass Spacer with High-Modulus Structural Silicone

Designed to meet the toughest commercial glazing demands, the JEB 3Seal HM+ spacer features triple seal technology, including an improved secondary seal made out of high-modulus silicone, as well as a hot-applied captive polyisobutylene (PIB) primary seal and a pre-applied acrylic adhesive for spacer to glass bonding.


The improved JEB 3Seal HM+ spacer offers significant aesthetic and energy-efficient advantages over traditional IGU spacers.

The high-modulus silicone secondary seal minimizes PIB migration, providing clear, straight sightlines. It also offers 35 percent higher design strength, allowing for a narrower air cavity in an IGU, and 10.4 percent more argon gas retention than standard sealants, based on ASTM 2190 testing. An IGU incorporating the JEB 3Seal HM+ spacer will retain its argon gas longer over other insulating glass systems, maximizing energy savings and extending the units service life.


Traditional metal spacers are highly conductive, the JEB 3Seal HM+ spacer is made from thermoset structural silicone with integral 3A desiccant, which allows for minimal thermal conductivity, higher edge-of-glass temperatures, and an improved condensation resistance factor. With its T-shaped design, the JEB 3Seal HM+ spacer also offers shock-absorbing properties that counteract glazing stresses caused by wind, snow, driving rain, fluctuating temperatures, and barometric pressure.

Download E-Z Specification

Contact Gary McQueen for Architectural Assistance:


Learn how JEB 3Seal HM+ Improves Wall Performance, Mitigates PIB Migration, and Delivers an Extremely Straight Sightline.

3Seal® Fabrication
Product Makeup


  • Limits PIB Migration: Superior quality, fully automated hot-applied PIB application, acrylic adhesive and spacer’s unique t-shaped design limit PIB primary seal migration

  • Improves Argon Gas Retention: High-strength and high-modulus properties minimize stress on PIB primary seal and improve argon gas retention rates

  • Delivers an Extremely Straight Sightline: Robotic spacer application and high modulus silicone deliver a sleek sightline and thin profile, delivering a clean aesthetic for the toughest commercial glazing demands

  • Increases Condensation Resistance Factor (CRF): Minimize condensation and maintain ideal humidity levels, especially critical with healthcare, luxuryhigh-rise and other demanding glazing installations

  • Improves Sound Attenuation: Use wherever noise from airplanes, trains or automobiles may be a concern for building occupants