A spirt level or bubble level is an instrument designed to indicate whether a surface is level or plumb

Spirit level

Spirit level
Size	Carton size	Qty/ctn	G.W./N.W.
30cm	32*35*31cm	60	14/13 kg
40cm	42*35*31cm	60	18/17 kg
50cm	52*35*31cm	60	22/21 kg
60cm	62*35*31cm	60	26/25 kg
80cm	82*30*20cm	30	19/18 kg
100cm	102*30*20cm	30	21/20 kg