L H Dottie Co LB300 Threaded Conduit Knockout Closer

Product Description

The L H Dottie Co LB300 is a threaded conduit knockout closer used to seal unused knockout openings in electrical enclosures, junction boxes, and panels. Weighing 3 pounds, this unit is sold individually and provides a clean, code-appropriate closure for open conduit knockouts that are not in use. Electricians and electrical contractors install this fitting during rough-in and finishing work to maintain enclosure integrity and meet NEC requirements for closing unused openings in electrical boxes and cabinets.

The LB300 is suited for residential and commercial electrical installations where unused knockouts must be sealed. Typical applications include junction boxes, pull boxes, panelboards, and other metallic or non-metallic electrical enclosures. It is installed wherever an open knockout would otherwise leave an unsealed entry point inside an energized enclosure.

Key Features

• Threaded design for secure, tool-assisted installation in knockout openings
• Sold individually for targeted replacement or single-point repair work
• Appropriate for use in standard electrical enclosure and panel applications
• Supports NEC compliance by closing unused conduit knockout openings

Compatibility

Designed as an OEM-style replacement closer for standard threaded knockout openings in residential and commercial electrical enclosures and junction boxes.

Installation Notes

Installation is typically performed by a licensed electrician. De-energize and lock out the panel or enclosure before beginning work, in accordance with OSHA lockout/tagout procedures. Thread the closer into the knockout opening using appropriate hand tools until seated securely. Verify the opening is fully covered and meets applicable NEC requirements for enclosure integrity before restoring power.