I'd had the MightyOhm Geiger counter kit in my wish list for some time and finally decided to buy it. It's a well designed little kit, easy to assemble, with clear instructions. All required parts were included. My kit worked without any troubleshooting. Cursory comparison to a Ludlum Model 3 and CD V-700 shows comparable rates using the same check sources. Super nice that pre-tested GM tubes are available, it really takes the guesswork out of it.