Glass on Glass question

I bought a per(x)
What size ashcatcher will it take? 14mm or 18mm? Is there any way to measure it?

here are pics of the pipe and the ashcatcher i plan to buy

ok it dont wanna work
http://us.st11.yimg.com/us.st.yimg.com/I/yhst-82573438376655_1965_5698859

im thinkin its the 14 cause it costs more than the 18 most likely cause its more popular.

But before i buy it does anyone disagree?

If you don't know how big it is, don't buy an ashcatcher. Either measure it, borrow a friends to compare (if you know the size of his) or bring the downstem to the shop (cleaned well ofc)

Per(x) Multi Perc Tubes um it says right there 18mm...
14mm is a thing of the past... almost all new GonG pieces use 18mm standard.
And since a per(x) is a ph(x) knockoff i would think they would use the same sizes..... y didnt u just get a ph(x)... that site lists their per(x) at 170... i bought my ph(x) duo at $200 at a headshop. The quality is better two...
Per(x) Glass - Page 7 - Glass Aficionado Forums
might wanna check that out two... a guy ordered from them and recieved his shit in pieces.

yeah i got my shit in pieces. But when i was at the headshop with my stem. The guy fit one in it for me and said he didnt know the size number but he said it was the smaller of the 2

this blows. I wish i wasnt such a burnout and read the part where it says 18mm.

I dont even know if it was shipped yet. That place is horrible with returning emails. I emailed them friggin 3 times in 3 days, asking which one i need. They must of just laughed at what a retard I was