Got ahold of Summit costumer service this morning (after 45 min. on hold) and first informed them there one inch gauge didn't fit the bottle because it was not one inch like advertised, but 3/4 inch... Also if they would put in the description that it had a nut with a 4AN male fitting that would help... Soooo.. sending me a less expensive gauge with refund and told me to keep the old one...