#1C5 Rumen Cannula with rolled inner flange. 5 inch (12.5 cm) center diameter. Up to 3 inch (7.5 cm) body wall thickness. 2 lbs. For large cattle with 5 inch (12.5 cm) fistula. The #1C5 is recommended for large cattle where a 4 inch fistula has “stretched” to 5 inches. The #1C5 is similar to the #1C rumen cannula. Stopper included.