https://www.amazon.com/Lingketech-Connector-Adaptor-Straight-Accessory/dp/B08D6M5N1V/

I had the 810 so finding the 510 was easy in my order history

Term is drip tip. The V4 is 510 size, the M22 is 810. Links to each below.

810 size: Lingketech 810 Glass Drip Connector tip Screws Adaptor Straight Curved Accessory (USA Stock Arrive in 3-7 Days)-Curved https://smile.amazon.com/dp/B08D6M7JKS/ref=cm_sw_r_cp_api_glt_fabc_WCXR9FMWZDTJ0DS32V14?_encoding=UTF8&psc=1

510: Lingketech 510 Glass Drip Connector tip Screws Adaptor Straight Curved Accessory (USA Stock Arrive in 3-7 Days)-Curved https://smile.amazon.com/dp/B08D6M5N1V/ref=cm_sw_r_cp_api_glt_fabc_HCT8VK2CR4Z726E0PKPG?_encoding=UTF8&psc=1