What is the difference of IP67 and IP68?

For solar lights,IP67 is the same as IP68.There are three reasons as follows:

• IP means Ingress Protection.The international safety standard for IP is IEC60529.IP codes have the format IP××,where the ×× represent numerals from the coding scheme(see Table 1 and Table 2);

Numeral                     Characterization of Ingress Limit
0 or X                                       Not evaluated
1                                   ≥50.0 mm diameter object
2                                   ≥12.5 mm diameter object
3                                   ≥2.5 mm diameter object
4                                   ≥1.0 mm diameter object
5                                            Dust-protected
6                                                 Dust-tight
 Table I.The first numeral in an IP code indicates the degree of protection from solid foreign objects.

Numeral                         Characterization of Ingress Limit
0 or X                                                Not evaluated
1                                            Dripping water:vertical
2                                            Dripping water:15°tilt
3                                                    Spraying water
4                                                    Splashing water
5                                                   Jetting water
6                                            Powerful jetting water
7                                            Temporary immersion
8                                            Continuous immersion
Table II.The second numeral in an IP code indicates the degree of protection from moisture.

• In all practical applications,it is impossible for a solar light to immerse under water for long time because it couldn't be charged in such case.So IP68 for solar lights is nonsense.

• No solar light can pass through the IP68 testing for sure,because it can't be charged for a long time under the water.The IP68 expression in a solar light only be speculation gimmicks and attempts to mislead users.