Sapim 4.2mm nipple wrench is measured across the flats of square portion of the nipple. Compatible with 5mm Ebike nipples used with 13g (2.3mm) spoke wire diameter wire such as E-Leader and E-Strong.  

Note: If you are using 13G ebike spokes with a reduction nipples this is the wrong wrench.   

Technical Information:

• Suitable for 4.1-4.20mm dimension measured across the adjustment flats of the nipple. 
• COMPATIBLE with 5.0mm, 13G Sapim nipples sold with Ebike spokes.   
• NOT COMPATIBLE with Reduction nipples or standard bicycle spoke nipples with dimensions of 3.23mm-3.45mm across the nipple flats.