Welcome!  This is a Vintage Betty Dain Creations Stylist's SMock.  Wonderful find, MOD, FLower Power with O Ring Zipper Pull.  Full Metal Zipper, Two patch pockets,  high side slits/vents and front vent.  Entire smock is edged with cotton edging, some of which has a little fray on the interior..

From the look of the inner label/tag, this has been washed and worn plenty, but the outer fabric belies this.. as the colors are so bright, the fabric is strong, the zipper works great and there are no stains!

The only mention is that base of the zipper has been sewn shut... so the smock can be zipped all the way down but it doesn't come apart, so you step in and out or put it on over the head.

I'm not certain of fabric content but I'm guessing cotton blend.  It has a twill like feel. Could be all cotton too.

No size tag, Measurements place this at a  M-L
19" seam to seam across chest,, double it for a maximum of a 38" bust.
Top of shoulder to underarm, at arm opening is approx 8" or 16" arm opening circumference.
Length approx 29.5"
Approx 20" across hips.
Side and front vents are approx 8.5" from hem, so hips have some flexiblity.

Quick ship
non-smoking
odor free smock
thanks!