This quick connect coupling is great for connecting 5/16" OD tubing to 1/4" OD tubing. For use with Lg refrigerators, polyethylene & reinforced vinyl tubing. 5/16" OD x 1/4" OD Quick connect coupling to connect 5/16" OD tubing to 1/4" OD tubing For use with lg refrigerators, polyethylene & reinforced vinyl tubi