Slider (of a plastic baggie)

[mrb]

This appears in a list of kindergarten supplies for the classroom:

Gallon, Quart, Sandwich and Snack size SLIDER close plastic bags

bolsas de plástico que cierran con un ________:?:

[AngelicaDeAlquezar]

Bolsas de plástico con cierre. :)

(Although this might be different for other regions.)

[poli]

A Latin American friend of mine said that when he was a child the word
corredera was used for zipper. This surprised me because I have always
thought the word for zipper was cremallera or cierre.

[mrb]

Thanks. I used the suggestion of someone who said: bolsas de plástico con cierre deslizante.