From the manufacturer

TWIST Bottle Connector for TWIST 450, 590, 600, and 750 Bottles. Not compatible with TWIST 800 or KEEGO Bottles.

Easily attach your new connector by placing it in the Connector indent on your Bottle and locking it in with a coin. Replace your connector on your existing set or add to a Replacement Bottle.

Features

• Compatible with TWIST 450, 590, 600, and 750 Bottles
• Not compatible with TWIST 800 or KEEGO Bottles
• Compatible with all TWIST Bases: Bike Base, Tex-Base, and Uni-Base