You may see various sites like eBay and Aliexpress offering quite cheap GSM switches which operate via an installed telephone SIM card inserted into a device. You just send a text to the device turning it on or off. There is a charge to send the text, unlike with our product.
If you intend going this route be very careful when buying these GSM switches. They are quite cheap but only work on 2G and are useless or very soon will be useless once 2G is completely phased out around the world.
Units which work with 3G or 4G are much more expensive, typically over €120. (https://www.aliexpress.com/item/32775341822.html). Remember that 3G is likely to be phased out shortly as well!
Also, you need a 12v power supply with the above item which isn’t supplied and unless your Mandarin is up to scratch, you could have trouble with product support. We provide support in English and German.