Boiler Handhole Plate Only. 2-3/4" X 3-1/2" Obround, Curved, 36" Dia. (CB 104-436)(PHH4D) Boiler Handhole Plate Only. 2 3 4" X 3 1 2" Obround, Curved, 36" Diamter All handhole plates come furnished with stud bolt, nut and washer. Replacement Part for CB 104 436 CB and Cleaver Brooks are registered trademarks of the Cleaver Brooks division of Aqua Chem, Inc. H. C. Oswald Supply Company is not an authorized manufacturer or reseller of Cleaver Brooks parts and products. The products described herein are not manufactured or authorized