I have 3 spec 1, green mosters , pre 2000 when he changed plexiglass .have $710 in all 3 and bid way higher on last two. This frees up newest one to hunt with . also have slate world class before they were called spec 1's . I have killed 9 grand slams and 2 royals and had at least One slate and one glass Cody with me on every One.Some have been the green monster most have been the cheaper Cody ll . They were he original high frequency calls . no-one had that sound in the 1990's . the important thing with any callmker is CONSISTENCY. Why do I buy expensive calls, because I know they will perform. And yes Bill Zearing calls have ALWAYS been consistent since the 1990's. Spend $40 or over $200 on them and they are turkey killers in good hands.