... >assembly size: dia56 x L.64.9mm 3>steel planet gear PG56 series gearbox-size: Ø56 mmx(37.1-95.2 ... shaft<0.05mm-thrust play of shaft<0.3mm-Pinion gear hole:Ø6mm-all reduction ratio:1/3.6, 1/4 ... , 1/2184 ,1/2321 ,1/2913, 1/2740, 1/3439Our gear boxes pass CE,ROHS and ISO9001.One model: PG56-102K ... size as following 56mm with round motor flange dc planetary gear box