Missing arm bar on graco duo glider. Would like to attach Graco Snugride carseat.

SOURCE: Graco Duo Glider LXI -

you need to make sure both seats are upright, the storage basket bar is up and locked in place, the canopies are pulles back and out of the way, and when you lower the stroller to fold it shut, make sure the wheels are not sideways and in the way. the front wheels need to be straight, if they are crooked the stroller will not shut completely. if you still need help i'm at [email protected]

SOURCE: our graco tandem duo

http://www.gracobaby.com/ReplacementParts/Pages/ReplacementParts.aspx

SOURCE: cant open folded graco duoglider 7024

Have you tried pushing down on the red lever on the side of the stroller to release the lock?

SOURCE: How do I fold up DuoGlider???

Folding up duoglider. Fold the botom basket down. I always take off the front wind breaker ( infants cover). It will just pop right off. Then locate the front handle of glider, slide red button to the right and twist.

SOURCE: Graco Snugride Carseat postion in 1304tw Babytrend double stoller

Visit Baby Trend to download a pdf manual from strollers for you specific type of stroller. http://www.babytrend.com/

Check the instructions to learn how the seat should be attached. Did say doesn't work for all brands.