Sliding mechanical closure with color position indicator

The invention claims a flexible storage bag (20), wherein a: Opening (30) and closed opening coloured detection unit (50), for sealing the mechanical sealing device of opening (40) and for sealing the sliding block of mechanical sealing device (60). The slide block comprises an opening (70); when the sliding block end of the mechanical sealing device position is configured along the side of the opening and printing detection unit (50), a coloured the detection unit (50) and opening is obvious. Coloured detection unit (50) is located near mechanical gate seal head, wherein the locating for mechanical seal device can completely the position. The colored detection unit and is different from the periphery of the plastic arranged plug-in or can be printing or the spraying in the recesses position.