GB 20052-2024 Chinese PDF GB/T 45471-2025 2-2025_Chinese: Optics and photonics -

2-2025_Chinese: Optics and photonics - Test methods for telescopic systems - Part 2: Binoculars (Chinese: 光学和光子学 望远镜系统试验方法 第2部分：双筒望远镜)

GB/T 45496-2025_Chinese: Motor vehicle product recall - Guidelines for information defect assessment (Chinese: 汽车产品召回 信息缺陷评估指南)

headed (Chinese: 成型模 带头导套和带头定位导套)

2-2025_Chinese: Petroleum and natural gas industries - Materials for use in H2S-containing environments in oil and gas production - Part 2: Cracking-resistant carbon and low alloy steels

English versions: GB 30253-2024

GB 20052-2024 Chinese PDF GB/T 45471-2025 2-2025_Chinese: Optics and photonics -GB 20052 2024_Chinese: Minimum allowable values of energy efficiency and the energy efficiency grades for power transformers (Chinese: ) Note Careful: Text of PDF is in Chinese (not English). Delivery (PDF in Chinese): 2 working hours typically, ASAP English versions: GB 20052 2024