I would actually say that that depends, as far as fit goes. Top hats I buy straight from Davies Molding/Daka-ware in Chicago, they're still made with the original injection die. The round ones I buy vintage originals, they're not that expensive because blade switches using them were very common in the 50s, especially on tube testers. I've found that if you search through a pile of daka-ware made ones, you will find all manner of fits, especially on the vintage ones, ranging from decent at best to tight as all hell. I use the latter end of the scale the most.