The present invention provides a diffraction grating element that allows the temperature control mechanism to be dispensed with or simplified. , optionally a C1-30 acrylate monomer, a nitrogen-containing polar monomer, and a polymerizable epoxy-containing monomer, with the monomers being present in an amount such that the copolymer has a Tg50 C. A lever arm is provided with a bore that fits over and is complimentary to the boss, and the lever arm is held in place on the boss with a removable threaded fastener that secures the lever arm and the cylindrical pin portion together. In this way, upon copying data between databases with different kinds of attribute information that can be set, the destination database can hold the attribute information of the source data.