Newmar , owns patents on slides and I think they make their own parts , but I'm sure others with up to date knowledge will be along shortly.
P.S. I lived 55 years in Kelowna, they wouldn't name a street after me so I left town.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.