High quality stainless steel headers available in three different drops to fit most applications. To determine the drop you need, measure from the face of the of the exhaust port down to the center centerline of the inlet on your canister or tuned pipe.  Below is a list of some popular planes and what headers and header drop distances fit them best:

Note:

70cc 2 into 1 headers inc PTFE Joiner and Clips

AJ Aircraft

Laser with GP76 use 90mm drop 2 into 1 header with MTW TD110H canister

Extreme Flight

 91" Extra with GP76 use 60mm drop 2 into 1 header with MTW TD110H canister.

Flex Innovations

Mamba  GP76,  2 into 1  40mm drop header, MTW TD110H