what is gamma-butyrolactone (gbl)

Other Names: GBL Wheel Cleaner
CAS: 96-48-0
EINECS: 202-509-5
Appearance: Colourless oily liquid
Melting point: -43.53 °C
Boiling point: 204 °C
Molar mass: 86.0891 g/mol
Density: 1.13 g/cm?
Formula: C4H6O2
IUPAC ID: Dihydrofuran-2(3H)-one