Native Small/Medium/Large V3 Frames Diaphragm Elk Calls - 3 Pack - Easy to use. Powerfully loud. Total Control of the notes for bugles with tender and soft cowithcalf sounds. The V3 frame is a simple design offered in 3 sizes that fits absolutely everyone with the same performance no matter the size. Three sizes of a low profile frame come in three weights of latex that are simple to understand and use. Ultra light, Medium and Heavy.