Many times a patent is just not worth getting. I wouldn't patent a small product like this because it appeals to maybe one out of several thousand people.
Save your money, just manufacture it and sell it to detectorists. I patented an item and lost money even tho for over 3 years it was in Harriet Carter, Home Trends, Get Organized, Walter Drake, Miles Kimball, etc catalogs. Wasn't a big enough money maker for the catalogs and eventually got kicked out of each. My best product (since 1999) is in a niche market (does not appeal to the general public) has no patent, I manufacture it alone in my basement and sold more than $1,000,000 worth from my website to small and large corporations, state and federal government. Again, no patent. After expenses and taxes I'm not getting rich but this tiny business works for me and I still have enough time for metal detecting.