water cap

[cm1466]

hi all
I can't seem to remove the water cap on the radiator bottle, it has two arrows and a sort of book symbol? and looks like you twist and press, does anyone know? i just want to check my water level in this heat and refill if have to..
thanks : )

[stevo67]

Metal type press down on cap whilst turning,plastic type old rag over the top then adjustable grips.both ways done when the engine is stone cold.