You can buy a geomantic compass at an antique stall. Most people in Henan are selling it. There's a compass in the middle, and there's a lot of gossip about heavenly stems and earthly branches and the zodiac outside, but you have to understand that it's not an antique, but a contemporary handicraft at most, and you can kill it at a very low price.
If you want to buy a compass, a compass is a compass, just like a compass. You can buy it in an outdoor shop. The quality is good, and some are cheap. Because there are too many stores in Hangzhou, I won't list them one by one. You can find one near you online.