rotary hook for Industrial sewing machine parts. Max sewing speed:4500r.p.mAperture:Φ7.94mmSuitable for: JANOME:DB-J705,J706 BROTHER:DB2-B706-5,B755-5 SINGER:400W,402W,391U CHUAN NENG:CN-110 (open auto-lubrication system) OUR SHOW ROOM:OUR OFFICE :OUR PACKING: ROTARY HOOK