Mullion Mate® Partition Gap Closures
Mullion Mate® is an adjustable partition closure that creates the perfect transition between window mullions, windows, and partition walls.
Mullion Mate® is an adjustable partition closure that creates a seamless transition between window mullions (curtain walls), windows, and partition walls. Aesthetically pleasing, these spring-loaded partition closures bridge the gap to fit a variety of openings and provide excellent noise reduction up to 60 STC. Finished to match mullions, factory cut to length, and arriving to the jobsite pre-assembled, Mullion Mate’s ease of installation creates the solution to an everyday problem.
Design Attributes
- For vertical junctions between partition walls and window mullions
- Finished to match mullions
- Clear, medium, or dark bronze anodized, and Champagne
- Field paintable finish
- Powder coated in standard or custom colors (AAMA2604/AAMA2605)
- Custom Finishes available upon request
- Factory spring loaded to fit a variety of opening sizes
- Pre-assembled for ease of installation
- Factory cut to desired height, maximum 192″
- Optional Mullion Mate end cap to finish partition walls

Mullion Mate® Profiles
Series 60
- Closes Gaps from 4” up to 8-1/2”
- Double Mullion Mate® design surrounds the window mullion, increasing STC up to 60.
- Patent Pending

Series 60 Sizes
Mullion Mate® 4 – 4″ minimum to 5-7/16″ maximum opening
Mullion Mate® 5.5 – 5-1/2″ minimum to 6-15/16″ maximum opening
Mullion Mate® 7 – 7″ minimum to 8-1/2″ maximum opening
Series 40
- Closes Gaps from 2” up to 14”
- Provides up to 56 STC

Series 40 Sizes
Mullion Mate® 2 – 2″ minimum to 2-15/16″ maximum opening
Mullion Mate® 3 – 3″ minimum to 3-15/16″ maximum opening
Mullion Mate® 4 – 4″ minimum to 4-15/16″ maximum opening
Mullion Mate® 5 – 5″ minimum to 6-15/16″ maximum opening
Mullion Mate® 7 – 7″ minimum to 8-15/16″ maximum opening
Mullion Mate® 9 – 9″ minimum to 14″ maximum opening
Series 30
- Closes Gaps from 2” up to 14”
- Provides up to 37 STC

Series 30 Sizes
Mullion Mate® 2 – 2″ minimum to 2-15/16″ maximum opening
Mullion Mate® 3 – 3″ minimum to 3-15/16″ maximum opening
Mullion Mate® 4 – 4″ minimum to 4-15/16″ maximum opening
Mullion Mate® 5 – 5″ minimum to 6-15/16″ maximum opening
Mullion Mate® 7 – 7″ minimum to 8-15/16″ maximum opening
Mullion Mate® 9 – 9″ minimum to 14″ maximum opening
Series 20
- Closes Small Gaps from 1” up to 2”
- Patent Pending

Series 20 Sizes
Mullion Mate® 1 – 1″ minimum to 1-7/16″ maximum opening
Mullion Mate® 1.5 – 1-1/2″ minimum to 2″ maximum opening
Partition Wall End Caps


Features & Benefits

Installation Options

Wall-to-Mullion

Wall-to-Glass

Wall-to-Glass
(Field Notch)
Videos
Finish Options
AAMA 2604 Powder Coat Finishes Download PDF
AAMA 2605 Powder Coat Finishes Download PDF
Antimicrobial Finishes
Green By Design
- Products contribute to LEED® certification
- In-House Finishes
- Biodegradable pre-treatment powder coat (no phosphates)
- No hazardous waste
- No VOC’s
- No Heavy Metals
- Reference our sustainable brochure & sustainability page for more information.
Projects
Product Data
Mullion Mate® Series 60 Consolidated Set
Mullion Mate® Series 40 Consolidated Set
Mullion Mate® Series 30 Consolidated Set
Mullion Mate® Series 20 Consolidated Set
Mullion Mate® End Cap Details
Mullion Mate® Series 60 Specifications
Mullion Mate® Series 40 Specifications
Mullion Mate® Series 30 Specifications
Mullion Mate® Series 20 Specifications
Gap Closures for Fire Rated Walls
White Paper (STC Acoustics)