Suggest Squirrel Glider (Petaurus norfolcencis) but not 100% certain without seeing tail.
Sugar Glider: Upperparts pearl-grey, blackish midline from between eyes to lower back. Blackish patches around eyes; alternate black and cream patches at base of ears. Edge of gliding membrane blackish fringed in white. Underparts pale grey or creamy yellow. Tail slightly tapered; grey then blackish for terminal quarter, frequently tipped white. Muzzle short, rounded, strong 'Roman nose'.
hb 160-200mm; t 165-210mm; wt 90-150g
Squirrel Glider: Upperparts pearl-grey, blackish midline of varying width from between eyes to mid back, darkest and broadest on the head. Blackish patches around eyes; alternate black and cream patches at base of ears. Edge of gliding membrane blackish fringed in white. Underparts white, including sides of face to below eyes. Tail pale grey, blackish for terminal half to third; fur long, flouncy, especially at base, giving distinct taper.
hb 170-240mm; t 220-300mm; wt 190-300g
Is Sugar Glider, we will need to think about adding Kreffts Glider (petaurus notatus) -one of three distinct Sugar Glider Species now recognised. For background, https://academic.oup.com/zoolinnean/advance-article/doi/10.1093/zoolinnean/zlaa060/5870721