The LKB Grid Storage Box consists of 100 diamond shaped holes for storing up to 100 EM grids, either 3.05 mm or 2.3 mm in diameter. It is made from ABS (a copolymer of Acrylonitrile, Butadien and Styrene) which will not tolerate temperatures above 70 degree C, while the lid is made of Polymethacrylate (Flexiglas, Perspex), which should not be exposed to temperatures above 45 degree C. Neither the box or the lid will resist organic solvents. The box measures 3" (L) x 2-1/8"(W) x 1/4"(H) and it comes complete with 10 index cards.