Cool! Never heard of this. I do not mind 5$ easily made. Recently, I saw a product I am interested in
https://www.amazon.com/Flagpole-Energy-Battery-Illumunation-Vont/dp/B00YBDA7DC/, a solar flag pole light for 30$. Now I can take it with 5$ less. It will be the best present for my father, as he is an ambassador and has many flags. It has a long-lasting battery, an utterly automatic daylight sensor, and most importantly, it has a lifetime warranty. I really enjoy making an order on Amazon. It's fast, qualitative, and too easy.