See-through Version for OHP The see-through display and keypad of this calculator can be projected onto a screen through an overhead projector (OHP). This is useful when explaining the keypad operation and when explaining the steps involved in a calculation. EL-509RT EL-531VH/509VH EL-509V/531V OH-500L EL-500L OHP System By connecting your controller to a see-through display you can project the contents of the controller through an OHP. This is useful in class or at academic meetings. EL-99T EL-9900 EL-965T EL-9650 EL-96Tc EL-9600c EL-945T EL-9450 EL-94T EL-9400 PC-Link Kit Transport data from your calculator to your PC to make back-up copies and print the data. The data can also be edited on your PC. CE-LK2 EL-9900 CE-LK1P EL-9650/9600c EL-9450 EL-9400 Set-to-Set Communication Cable Data can be transported, and data and programmes shared, between identical models. CE-451L EL-9900 CE-450L EL-9650/9600c EL-9450 EL-9400 Data Collection System By connecting your graphing calculator to a commercially available data logger and sensor, you can upload experimental data to your calculator. For EL-9900 For EL-9650/9600c, EL-9450