Here's what Omnium has to say:

Spare Thru Axles for Omnium bikes.

Specifications

Front TA (All V3, WiFi & Titanium): 15×100, 125mm long, 17mm thread length, 1.5mm pitch

Front TA (CXC V3): 12×100, 125mm long, 13mm thread length, 1.5mm pitch

Rear TA (V3 & Titanium V3IR frames): 12×142, 172mm long, 19mm thread length, 1.75mm pitch 

Rear TA (WiFi): 12×142, 174mm long, 21mm thread length, 1.75mm pitch 

Titanium Rear TA (For V3 and WiFi): 12×142, 167mm long, 1.75mm pitch