C-7 The first in a series of 3. The "C-7" tank is perfect for your chopper with it's long sleek body and flat bottom. The "C-7" tank is beautifully formed from 16 gauge steel and completely TIG welded and pressure tested. Tanks can be built narrow or wide -2 1/4" tunnel standard, tunnel can be adjusted to sit high or low on the frame Screw bung standard- Flush caps additional 4 -underneath mounts Choice of threaded petcock fitting either 3/8" NPT or 22mm