Montana Girl

Good evening all. My husband has given me the challenge of finding an answer from you all. While preparing for summer set-up and un-winterizing he found that the glide on the top of the middle shower door is missing. Does anyone know where to find replacements? We have a 2018 Montana 3820FK. Thank goodness I had read somewhere within this forum about the shower doors rattling loose and getting broken. We secured those well and all is good there.