purchased on impulse about an hour ago because of the 19mm od, and threaded top cap... looking at the pictures there is no visible air hole on the top cap. the base must be vented, i'll definitely plug that hole and drill a new hole at coil height... maybe tap threads into the hole and thread a very short 3/32 tube to eliminate leaks. i will post pictures before and after in this thread
https://www.fasttech.com/search?x1

https://www.fasttech.com/search?x1
