The AA186 is a full sized tuba with a strong sound and superior intonation. The Allora 186 features a .770 inch bore with a 4 rotary valve design for outstanding response and smooth action plus a 17.75 inch bell for excellent resonance and projection. The design of the Allora AA186, inspired by the popular Miraphone 186 BBb tuba, is great for schools and student musicians at an affordable price.