Poly Wallet features an eye-catching ultra-color that you can easily keep track of it. Archival-safe, durable polypropylene material is also acid-free, water-resistant, and tear-resistant. The 3-1/2" expansion holds up to 800 sheets of letter-size paper. To withstand everyday use, Poly Wallet also offers a cloth gusset with sewn edge trim and heavy-duty elastic cord that secures the flap.