These are not 45 adapters. These are made to resemble them. This listing is for two purple flexible Reel to Reel spool holders/retainers. designed and made in the USA. These are flexible enough to allow for easy placement and removal with no hassle. The center hole is 1/4 of an inch in diameter. Want a different color? Please contact me. If I have the color I would be glad to create a set in your preferred color. Looking for flexible or rigid replacement parts? Tell me what you need. I can create small items in plastic or rubber to solve your problem or replace hard to find parts. Please ask any questions prior to purchase.