The Korean-designed and manufactured ER-6 uses a robust plastic base with modular circuits that can be easily attached, removed and interchanged. We have had positive feedback regarding this kit and it is popular worldwide. The software is easy to understand and to follow, and grade 7 and 8 students will have no problem making and programming autonomous robots. The manufacturer has proven to be very helpful in regard to technical questions and troubleshooting. If you are interested in seeing what other kits are available, we have an ever expanding Education Corner as part of the RobotShop Learning Center.