H-Jamb vs. Bulb Seal: Which Shower Door Seal Do You Need?
Both close the gap along the vertical edge of the door. The right one depends on what the door closes against and how big the gap is.
H-jamb
A clear rigid seal that pressure fits onto the edge of a fixed glass panel where the door closes in a straight line (180°). The door closes against it. Examples: CRL P380HJ for 3/8" glass, CRL P120HJ for 1/2".
Bulb seal
A round, soft bulb that compresses as the door closes. It comes two ways:
- Clip-on, pressure fit onto the glass edge, made for one glass thickness (CRL PCR10 for 3/8").
- Tape-on, stuck to the glass edge or wall with VHB tape and chosen by the gap it closes, not the glass thickness (CRL SDTB).
Which to choose
| Your door | Use |
|---|---|
| Closes against a glass panel in a straight line | H-jamb |
| Hinge side, or against a wall, small gap | Bulb seal, or an 'H' wipe like CRL P375HW |
| Uneven gap or wall that isn't plumb | Soft bulb seal (it compresses to fit) |
Use our Seal Finder
Pick your door, point to where it leaks and we'll show only the seals that fit your glass. Takes about 30 seconds.
Products in this guide
Clear 'H' Jamb, 180°, for 3/8" Glass
Clear 'H' Jamb, 180°, for 1/2" Glass
Most commonClear Bulb Seal for 3/8" Glass
Clear Vinyl Bulb Seal, 5/32" to 7/32" Gap
Most commonMulti-Purpose 'H' Wipe for 3/8" Glass
Common questions
What is an H-jamb on a shower door?
A clear rigid seal that fits on the edge of a fixed glass panel where the door closes in a straight line. The door closes against it.
When should I use a bulb seal on a shower door?
On the hinge side or where the door meets a wall, especially if the gap is uneven: the soft bulb compresses to close it.