Cylinder won't fit

The cylinder or tank will not fit

UK and EMEA: the cabinet takes up to 13 kg, 587 mm high, 318 mm across (round) or 289 mm (square-based); its base must sit flat in the holder (the manual). US: a standard 20 lb tank, 18¼ in high and 12¼ in across; turn it so its collar matches the scale. A fuel gauge that reads wrong usually means a non-standard tank or one not hanging freely (US manual; cause is this guide's reading).