Very uncommon due to being extremely expensive when new, and REL manufacturing very few of them. REL tuners were more broadcast station air monitor gear than consumer FM tuner, and with prices to match. Then 1/2-1/3 the price of a new basic Ford, Chevrolet, or Plymouth sedan. The Precedent was REL (Radio Engineering Laboratories) last FM tuner. The company lost money on every tuner they built. And inspired the infamous Marantz Model 10 and 10b FM tuners, the models which forced Saul Marantz to sell the Marantz Company to SuperScope, Inc in 1964 due to losing money on the 10 and 10b FM tuners.