BLADE KNIFE FOR HONDA MOWER ROTARY MOWER FOR MODELS HT3813K1 , HT3815 MODEL - TECHNICAL SPECIFICATIONS LENGTH 490 mm CENTRAL BORE 21 mm OUTER BORE 10.5 mm CENTRAL BORE INDEX 88 mm CODE: 1320233 ORIGINAL CODE: 72511-763-C00 , 72512-750-B00 , 72512-750-A00 , 72512-751-107 SR