2K Designs Staph Check Vinyl Waterproof Twin Size Innerspring Mattress & Box Spring Staph Check Vinyl Waterproof Twin Size Innerspring Mattress & Box Spring. 357 innerspring verticoil unit, with 13 3/4 SH gauge unit and 6 gauge border. 12 double edge guards-border support, Poly board fiber on both sides, Vinyl plasticized fabric. Wood foundation, Border is vinyl plasticized ticking. Meets federal standards 1632 and 1633 fire code.