Janome Needle Threader Unit see below list for model

Janome Sewing Machine Needle Threader Pin (Screw On Type) -

This threader will replace in the same way just unscrew the small screws attaching the threader then attach the new one and realign with a new needle, best to replace the needle at the same time

Fits Machines listed 

 MC5700/3500/2039/2139/ENX24,JL300,Jubilee85

10000, 2039, 2039SN, 2041, 2041LX, 2041NX, 2049 Harmony, 2049LX, 2049NX, 2049SX, 2139 Harmony, 2141S, 2200, 2522, 3000, 3500, 4000, 4023, 4123, 4800, 4800QC, 5000, 5018, 5024, 5124, 6018, 660, 662 JEM SILVER, 8100, 9000, AQS2009, DC5100, DE5018, DE5024, DE5124, ENX24, HF3000, HF5024, Jem Gold 660, Jem Gold Plus, JP720, JP760, MC2400, MC3000, MC3500, MC4000, MC4023, MC4800, MC4800QC, MC5000, MC5700, MC8100, MC9000, ME4123, XC33, XR33