Based on this product's specifications, here are some alternatives and similar models
Sealed Lead-Acid Battery NPP NP6-5Ah 6V AGM, 5 Ah capacity
Summary description:
NPP NP6-5Ah is a sealed 6V AGM lead-acid battery with 5 Ah nominal capacity. Designed for standby power, alarm systems, emergency lighting, small UPS units and portable devices, it provides maintenance-free operation, leak-proof design and reliable discharge characteristics. Suitable for indoor installation and short-term backup applications.