Safety interlock lid prevents operation unless lid is securely in place. Features 1/4" durable acrylic construction. Includes 2 heavy, nonwarping trays (each 9.5 × 9.75 cm and each marked for easy sample loading), plus four 8-tooth combs. Simply place the first casting tray in the gel box, add buffer, and load gel wells; next, place second casting tray on top of the first, add additional buffer, and load second gel. Running both casting trays at once, each with 2 combs, gives the capacity of 32 samples in one gel box. Allows the flexibility of running either one or 2 gels in the same gel box.