I got the delrin replacement caps for the pyrex tank yesterday and put them on the 7ml pyrex tank.  I have to say that I prefer these caps to the grommets.  Not to say the grommets are bad, but these caps make refilling the tank so much easier.  I think the grommets are a nicer touch on the sidewinders though, especially now that you got them in different colors.
	
		
			
		
		
	
			
			 
				
		 
 
		 
 
		 
	 
 
		 
 
		 
 
		 
 
		 
 
		