I have the Celestron Nexstar 102 SLT. Got it from Costco (as a gift). I’ve added the GPS positioning unit, got cables and software for it but have yet to figure out how to make it locate itself and then find stars, planets, etc… It seems simple but it’s not as plug and play as one things. I’ve tried to align it and lock in it’s GPS location. Again, turn it off and it’s square one when you power it back up. Wife also me the sun filter and extra lenses. I live near a big city but it’s pretty good for the price and lens ability. But unless you already know what your looking for, forget the GPS addon. It’s a waste.