2 sizes of dehorners in one. ID=15/16" O.D. 1 1/4" on one side. ID 3/4", O.D. 1" on the other. 110 volt w/thermos. Solid brass with heavy duty heating element stays hot enough to do both horns. Allow 15 minutes to heat up to proper temperature. 110 volt, 320 watts. Large 1" i.d. end for older calves 2-12 weeks old. Small 3/4" i.d. end for baby calves 3-10 days old.