Check the listing for details. LYSO 2×2 Crystal Array (4 pixels), Gamma Radiation Scintillator.. Condition: Seller refurbished. Listed at 50.00 USD. LYSO scintillation crystal pixels ! These are premium pixels saved from scrap scanners, and cleaned up ready for your projects, and builds. These are being sold at a competitive price, almost 1/4 the new price and even less then online competitors. Each array measures 8822mm, manufactured by SaintGobain. These pixels are great for mini scintillators using SiPM's or as a array attached to Photomultiplier tubes. Lyso has a great emission spectrum well suited for use with Bailkali PMT's, or SiPM's. Lyso is a fairly dense crystal, even denser then BGO but with better light yeild and greater resolution. With a expected yeild of 7-8% @66kev, and no moisture sensitivity, these make great detectors that can out preform most Ebay NaI ! These also make great check sources for pre-existing spectroscopy set ups, or as demonstrated piecework a element collection. LYSO has a natural radioactivity consisting of gamma rays from natural Lu-176. This does provide a slight detector background, but can be used for a quick self check and calibration source, and with most consumer softwares can be subtracted with background. Pick up your check source while they last ! Or Buy multiple for a great detector array build ! ~ J L Luck Labs Instrumentation.