Fire Extinguisher 2.5 pound ABC
See below from page 23 of the Best in the Desert Rule book
FIRE EXTINGUISHER Each vehicle must carry a portable UL approved minimum 2.5-lb. ABC-class dry chemical type or equivalent Halon, AFFF Foam, Novec 1230, FE-36 fire extinguisher. Fire extinguisher must have a gauge, be fully charged, and be easily accessible from inside of the vehicle. An additional minimum 5-lb. ABC-class, dry chemical fire extinguisher or foam equivalent must be mounted on the exterior of the vehicle. The mounting must be in such a manner as to prevent damage to fire extinguisher during rollover and must be marked in such a manner as to allowing persons not familiar with vehicle to easily find fire extinguisher. On-board fire extinguishers are highly recommended. Portable and on-board fire extinguishers must have a current (less than one year old) fire marshal’s seal and attached label. Class 2000 only will be allowed a minimum of 2.5lb ABC-class, dry chemical fire extinguisher or foam equivalent mounted on the exterior of the vehicle.