I have one of these. You can find them cheaper. https://m.ebay.ca/itm/GQ-GMC-320-Pl...592680?hash=item19f15d18e8:g:gckAAOSwRLZUH3JPPurchases made through these links may earn this site a commission from the eBay Partner Network
hi i use one of those https://www.amazon.de/Soeks-01M-Rad...&qid=1514538463&sr=8-15&keywords=geigerzähler and just hear if it clicks is not enough