Brass-Seal™ Forged Brass Mail Slot
ASTM E283 Verified · Intertek
ASTM E283 Verified · Intertek
Energy Savings Estimator
Calculate Your
Annual Savings
Annual Savings
Enter your ZIP code to get a savings estimate matched to your local energy rates and climate. The Brass-Seal is among the first mail slots held to the same independent standard as windows and doors. Based on Intertek ASTM E283 test results.
Your Estimated Annual Savings
Brass-Seal™ Performance
Letter Size — 8.00" x 2.25" opening
kWh saved per year
estimated savings per year
Magazine Size — 11.375" x 2.50" opening
kWh saved per year
estimated savings per year
Estimates based on Intertek ASTM E283 Report No. T4376.01-301-44-R1 (April 2026) and regional energy rate data. Actual savings vary by door condition, installation quality, and local utility rates. This estimate may be attached to a utility rebate application. Full laboratory report available upon request: info@blockouttheair.com.