NOTE : Oil your orings with a veg oil of your choice, before using this product
This is for the v4 in a 14mm male (18mm male coming soon) glass vortex top only,
always keep your orings lubed and hold glass piece from the base of glass, twist slightly to place and remove from base of heater.
This ad is just for the mouthpiece and it will fit the v4. it is thin and has worked great for me, but it will brake if you do not handle it properly.
when i started over 8 years ago, i wanted a glass pathway. something about metal just did not seem right, finally they were able to make one to my specs. and you can now shelve the metal top piece.