CPI - Roof Vent Cap 1-1/2 Black - Part #43B cleaned product image 1
CPI - Roof Vent Cap 1-1/2 Black - Part #43B cleaned product image 2
Custom Plastics 43B black RV plumbing roof vent removable cap with molded manufacturer markings
Custom Plastics 43B black RV plumbing roof vent removable cap side profile and vent opening
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CPI - Roof Vent Cap 1-1/2 Black - Part #43B cleaned product image 1CPI - Roof Vent Cap 1-1/2 Black - Part #43B cleaned product image 2Custom Plastics 43B black RV plumbing roof vent removable cap with molded manufacturer markingsCustom Plastics 43B black RV plumbing roof vent removable cap side profile and vent opening

CPI - Roof Vent Cap 1-1/2 Black - Part #43B

CPISKU: 43B
Added to catalog: May 08, 2026
Last product update: July 13, 2026 at 9:15 PM
$4.99 $9.98
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In stock (30 units), ready to be shipped
Availability details
Elkhart RV Parts warehouse0 ready to ship
ERVP overstock warehouse0 available
This quantity is stocked at ERVP. See the delivery estimate below for the current expected window.
Delivery Estimate August 30 – September 2
1-Hour Cancellation Window

1-Hour Cancellation Window

You'll have 1 hour after placing your order to update your shipping address or cancel completely.

After that, we begin coordinating with our vendors to fulfill your order — at that point, cancellations and address changes usually aren't possible.

If you're unsure about anything, please reach out before ordering or cancel within the window.

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Verify before ordering: Match Custom Plastics part number 43B, the black finish, your vent-pipe outside diameter, and the mounting pattern shown in the physical product photos.

Custom Plastics part 43B is a black two-piece RV plumbing roof vent assembly. It includes the roof-mounted vent base and the removable protective cap shown in the product photos.

Verified Product Details

  • Manufacturer: Custom Plastics
  • Manufacturer part number: 43B
  • Type: RV plumbing/sewer roof vent
  • Color: Black
  • Construction: Two-piece base and removable cap
  • Supplier size callout: 1-1/2 inch
  • Published compatibility: 1-1/4 inch to 1-1/2 inch outside-diameter vent pipe
  • Published overall size: approximately 5-1/4 inches in diameter by 3 inches high
  • Material: Polypropylene

Fitment Notes

Vent-pipe dimensions can be described differently across supplier catalogs. The manufacturer catalog and ERVP packing slip call this a 1-1/2-inch roof vent, while established distribution catalogs list compatibility with 1-1/4-inch to 1-1/2-inch outside-diameter vent pipe. Measure the outside diameter of your existing vent pipe and compare the base, cap, and mounting pattern before ordering.

What’s Included

  • One black Custom Plastics 43B roof-vent base
  • One removable black vent cap

Not included: Mounting screws, putty tape, sealant, and other installation hardware.

Installation Reminder

Remove the old vent assembly, clean the roof surface, and install the replacement using the sealant and fasteners appropriate for your RV roof construction. Seal all mounting penetrations according to the RV manufacturer’s requirements. If you are unsure about roof sealing or plumbing-vent requirements, have the installation completed by a qualified RV technician.

Frequently Asked Questions

Is the cap included?

Yes. Part 43B includes both the mounting base and the removable cap shown in the physical product photos.

Is this vent threaded?

The received ERVP part does not have the externally threaded lower neck previously depicted in the old catalog artwork. Confirm fitment by part number, vent-pipe outside diameter, and the physical mounting pattern.

Is mounting hardware included?

No. Mounting screws, putty tape, and sealant are not included.
100% Authentic OEM Parts

Factory-Fresh OEM Parts — the same brands installed in new RVs straight from Elkhart. Genuine, name-brand components made to order — never generic, never outdated. Sourced directly from the original RV manufacturers for perfect fit and factory-level quality.

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