9"x12" Black Poly Mailer Bags – 1000 Mailers Included Self-Sealing Closure – No need for tape or glue; the strong adhesive strip ensures a secure seal. Durable Polyethylene Material – Resistant to punctures, moisture, and tears for reliable protection. Opaque & Tamper-Evident – Protects contents from prying eyes and ensures package security. Professional Appearance – Clean, sleek design enhances branding and customer experience. The Boxery 9"x12" black self-seal poly mailer bags offer a sleek, durable, and lightweight packaging solution for all your shipping needs. These mailers are waterproof, tear-resistant, and puncture-resistant, ensuring your items remain protected during transit. The strong self-sealing adhesive strip provides a secure closure, eliminating the need for tape and offering a tamper-evident design for added security