Zero International 328FS Perimeter Seal with Extruded Neoprene and Intumescent Fire Stop

The 328FS is supplied in 84 inch lengths, clear anodized. One 84 inch piece covers a standard 7 foot jamb, so a single-door opening normally takes three pieces: two jambs plus one cut down for the head. Ordering one piece per opening will leave you short.

The intumescent fire stop. The NGP 108NA is a neoprene sponge seal in an anodized aluminum frame and the NGP 155V is a vinyl perimeter seal in a mill aluminum frame; both seal a gap, but neither carries the intumescent element the 328FS pairs with its neoprene. If the opening is a labeled fire door, the 328FS is the one specified for it. If you only need weather or light seal on a non-rated opening, the 108NA or 155V does that job.

No. The 328FS is a head and jamb perimeter seal only. The gap under the door needs a separate door bottom, sweep, or shoe, and on a fire rated opening that piece has to be rated as well. The Cal-Royal PG-601 aluminum channel gasketing is another perimeter product rather than a bottom seal, so it doesn't fill that gap either.

On an opening with no fire or smoke requirement, the intumescent fire stop in the 328FS is doing work you are not paying for in performance. Two vinyl-sealed perimeter gaskets cover that duty: the Cal-Royal PG-601, an aluminum channel perimeter gasketing with a vinyl insert, and the NGP 155V, a vinyl perimeter seal in a mill aluminum frame for commercial door weatherstripping. Both are frame-applied perimeter gaskets like the 328FS. The visible difference to note before you order is finish: the 328FS is clear anodized aluminum, while the 155V frame is mill aluminum, which is a different look if the seal is running next to existing anodized stop trim.

Be careful with the swap, because the fire performance on the 328FS comes from the intumescent fire stop built into the extruded neoprene seal, and it carries a UL10c fire rating and a smoke seal rating. The neoprene-family alternative is the NGP 108NA, a neoprene sponge seal in an anodized aluminum frame rated for a temperature range of -20 F to 200 F. The 108NA matches the 328FS on seal material and on the anodized aluminum housing, so it behaves similarly as a compression perimeter seal, but the intumescent element is specific to the 328FS. On a labeled door assembly, confirm the seal you install is the one named in the listed hardware for that assembly.

No, and it is the most common mix-up in this group because both mount to the frame around the door perimeter. The 602A is a nylon brush seal in an anodized aluminum housing; it seals with bristles, which pass air and are used where light dust and draft control is the goal. The 328FS seals by compression against an extruded neoprene element and carries a UL10c fire rating plus a smoke seal rating. If the specification calls for smoke sealing, a brush seal does not answer it. Where the 602A does earn its place is on a door that binds or drags, since a brush tolerates irregular clearance that a compression seal will fight.

Screw mounted through the clear anodized aluminum retainer. It's a perimeter seal, so it goes on the frame at the head and both jambs, with the neoprene bearing against the door face when the door closes. Screws are the only mounting method on the 328FS, so there's no adhesive-only option here if you're trying to avoid drilling a frame.

Compress-O-Matic is Zero's adjustable seal system. The 328FS uses it so the neoprene compression can be tuned after the seal is mounted, which is how you take up a door that doesn't sit tight against the stop without pulling the whole run off and re-drilling. It's also why these seals get specified for sound control work, where the seal has to make continuous contact the whole way around.

For acoustic work you want a compression seal, and the 328FS is one: adjustable neoprene squeezed against the door face all the way around. The NGP 159MA magnetic seal is the other approach, an anodized aluminum housing that pulls the door tight magnetically, also an 84 inch piece. What you don't want is the NGP 602A nylon brush seal, which sweeps rather than compresses and is aimed at dust and light draft, not sound.

They get to a tight seal by different mechanisms. The 328FS uses the Zero Compress-O-Matic adjustable system, so the extruded neoprene is set by adjustment to the door face and holds compression once dialed in. The NGP 159MA is a magnetic seal in anodized aluminum, which pulls itself to a steel door face rather than being adjusted into contact. That difference decides the specification for you: the magnetic approach depends on a ferrous door face, so on aluminum, wood, or fiberglass doors the adjustable neoprene of the 328FS is the applicable route. Both are offered at 84 inches, which is the standard single-door head-and-jamb run.

For a consistent anodized look down a corridor, the 328FS is clear anodized aluminum, the NGP 108NA carries an anodized aluminum frame, the NGP 159MA is anodized aluminum, and the NGP 602A uses an anodized aluminum housing. That lets you hold one appearance while varying the seal type by opening: neoprene with an intumescent fire stop on the rated doors, sponge neoprene or brush on the openings that do not carry a rating. The one to keep out of a matched run is the NGP 155V, which is built on a mill aluminum frame.

Both are frame-mounted perimeter gaskets built on an aluminum extrusion, so they occupy the same place on the opening. The seal element is where they part: the PG-601 is an aluminum channel with a vinyl insert, while the 328FS carries extruded neoprene with an intumescent fire stop and is rated UL10c and smoke seal. The 328FS also uses the Zero Compress-O-Matic adjustable system, and it runs 1 inch wide by .408 inch high in an 84 inch length with screw mounting. For a distributor matching an existing order, that adjustability plus the intumescent element is what separates the two part numbers.

Commercial. The 328FS is a commercial door hardware item, aluminum retainer with a screw-applied neoprene seal, sized for hollow metal and commercial wood frames. For a house door you'd be paying for a fire and smoke rating you have no use for.

Clear anodized aluminum, and that's the only finish the 328FS is offered in. It reads as a natural silver aluminum, so it sits well against clear anodized storefront and standard aluminum frames. Against a dark bronze or painted frame it will show as a bright line around the opening.