I just purchased a Mitsubishi WD-73840 and It said that it has a built in IR 3D emitter. When I look for compatible glasses it says that I need the startup bundle that has an IR emitter in the bundle. What I need to know is what glasses do I need since the TV has a built in 3D IR emitter. I need four glasses for my family and I want to get these glasses at the most reasonable price possible. If there is anyone on here who can help find the right one I will appriciate it greatly. I hope to hear from you soon. Take Care. Jonathan