What is the limit travel switch and its product packaging

What is the limit travel switch and its product packaging
1、the product picture of Bar limit switch Z91 series
2、the Z9-108 product picture of the Waterproof limit switch z91 series
3、a physical picture of the Z9-108 product of the limit switch z9 series
4、the packaging picture of the Z9-108 product of the limit switch z9 series: