Contractor bulk pack — 50 Double BOX SHELLs. Each BOX SHELL insulates a double outlet box or double switch box, creating a permanent airtight seal around electrical penetrations. No caulk, no tape, no licensed electrician required. IECC 2024 compliant. Works well for data connections as well.

Ideal for contractors and builders sealing multiple boxes on new construction or remodel projects. Save time and money with contractor pricing.

• 50 Double BOX SHELLs per pack
• Fits standard double-gang outlet and switch boxes
• Permanent draft stopper for electrical boxes
• Passes blower door tests — IECC 2024, R402.4 compliant
• LEED, Passive House, and net-zero ready
• No caulk, no tape, no licensed electrician required