I needed latex for a tube goose call and Harold Knight gave me some of the TheraBand green (heavy) at the NWTF in Nashville. The green works great for Canada goose calls, turkey gobbling and even snow/blue calling (with considerably more pressure). Both the TheraBand yellow and red are the ticket for tube turkey calls diaphragms, and a more accomplished caller w/ a tube style call, will probably like the red (a little harder to blow and master, but due to the thicker latex, a wider range of sounds. All of the TheraBand latex is available by the foot (shipping prepaid) by several sources on EBay