Credit: Joe Maring / Android AuthorityTL;DRThe OnePlus Watch 4 could swap the standard IP68 rating of its predecessor for an IP69 certification.Despite the rumored durability upgrade, the smartwatch is rumored to have a 646mAh battery, which is nearly identical to its predecessor’s.The display and size are likely to stay familiar with a 1.5-inch AMOLED in a 47mm case.A new certification and leak suggest the OnePlus Watch 4 will be more durable, while keeping almost the same battery size as the previous model.Certification listings are usually pretty dull. This time, though, tipster Sudhanshu Ambhore found the Watch 4 (model XL905) on the EMVCo database and shared a full specs sheet that deserves attention.