Glass has always been the cleanest option for baby bottles. Plastics can form micro scratches which trap bacteria and can be made with chemicals that leech out of the plastic.
This tempered glass baby bottle is in excellent condition and is a useable vintage piece. The rubber nipple which goes under the collar on to the bottle is the same standard size they still sell today.
This listing is for the glass Gerber branded baby bottle as well as the plastic collar and cap.