What is Thru-Skew?
Thru-Skew is a proprietary skewer interface developed by Trek Bikes. The system consists of a long bolt or skewer and a nut that receives the bolt or skewer:

The nut is held captive in the frame:

Thru-Skew comes in multiple lengths and designs. If you are unsure whether or not the skewer in your bike is a Thru-Skew skewer, we recommend viewing your model of bike on the Trek website to determine what type of skewer your bike uses:

Can I attach a kid trailer to the rear axle on my Thru-Skew bike?
Absolutely! We have developed an adaptor specifically for attaching KID trailers to Trek Thru-Skew bikes – our ADA010 adaptor.

The ADA010 Thru-Skew Adaptor is compatible with the rear dropouts of all Thru-Skew equipped bikes, and comes with a spacer to adapt ADA010 to either of the two skewer lengths found on these bikes.
Do you make an adaptor to attach my Thru-Skew bike to a indoor trainer/BOB trailer/FollowMe tandem/Burley COHO trailer?
Currently, we only make one Thru-Skew adaptor, and it is only for attaching a KID trailer. We do not manufacture adaptors to attach Thru-Skew bikes to any other sort of accessory.