Dee, I haven't been as thrilled with my 2 pyrex drip tips that I got from John. Since each one is made differently, no two will ever be alike. My clear tapered drip tip just does not have enough glass below the o-ring to hardly put into a carto. If you look at it side ways, it will fall off....if it hasn't already. My cobalt blue pyrex is not much better, and this is AFTER I had to send the first 2 I got back. They were both worse if that is possible. For $15 each, they sure as hell should fit perfect. My $3 delrin fits perfectly, but my $15 pyrex hardly fit at all. Kinda still pisses me...I've lost my clear one about 3 times already, but since it happened at home, I finally found it each time. No way am I taking it outside my home. Sadly, I like the pyrex tips best of all.....and can use them least of all. Go figure...