High-compress o-ring head for 45mm "70cc" Puch kits! This is the "new style" fin pattern.
No metal head gasket needed!
You can use these on Puch, Tomos, and a few Yamaha like QT50 and PW50.
Watch these heads if you're using a cylinder with a decompression hole. This isn't going to work well on Airsal 38, 44, or 45mm kits. Puch Polini 64cc kit won't work. Stock Tomos A35 either.