I’ve got a bunch from Shars branded as Tegara in both imperial end mill holders as well as ER20 collet holders. All were labeled as G2.5 20,000 rpm and have worked very well. I also bought 8 end mill holders from eBay seller niuniucme and have been happy with the quality. I spent a bit more than I had to on my BT30 tool holders and think buying known quality tool holders worth the extra money over the very inexpensive Chinese offerings.
-Jim