Breakaway transformer bases provide stability for pole mounting and accessibility to wiring at the bottom of poles. This base features 11″ to 13″ top bolt circle and 13″ to 15″ bottom bolt circle. Stands 20″ in height. Base can be ordered with hinged door option or with plastic access door. Available in 12 sizes and dimensions with variable bolt circles. Please note bolt pattern of pole for proper T-base selection when ordering. 1975 AASHTO Approved.