The Safe Backup Plus web interface offers two downloads for Synology: one for DSM 6 and one for DSM 7. Due to Synology packaging rules, these SPKs are not interchangeable.
SPKs are available for Synology NAS' which meet the following requirements:
CPU: x86_64, i686, ARMv7, or ARMv8
DSM version: 6 or 7
The Synology SPK does not include a graphical client. Instead, creating Protected Items and running backups and restores can be done from your Safe Backup Plus Server.