Front opening is 4". The rear opening is 10.5". The expansion of horn is 8.25". The length of horn is 26.5". Compatible netting sizes are 16, 18, 20, 22, 24, 26, and 28. Weighs 8 lbs. Dimensions: 26.5"L x 10"W x 12"H. See page 247 of our 2011 catalog for details.