The one's with 4 holes, are later made one's. Back in the 90's I made a call called super cutter box combo, that is the call I still use today & kill a lot of birds. That 5 hole you have is 1/2 of the combo. I changed to 4 hole so you could play on the back with more room. I still have a lot of the combo's but they are not for sale. I had to many hunter's using them wrong where I hunt & they was making hunting a little harder for me. I sold the last one in 2002 & now I have not come by one in the woods. I do not hunt fields only big woods & that is where the combo works great. hope this helps thanks al
