Line Interactive UPSs:

units incorporate an automatic voltage regulator (AVR). An AVR allows the UPS to boost or buck the incoming line voltage without switching to battery power. This allows the UPS to correct most long term over-voltages or more common under-voltages without draining the batteries. Another advantage is that it reduces the number of transfers to battery which extends the life of batteries.
Venus 2nd GEN – SBP-TBF UPS with Electronic Power Conditioner TBF™ (400VA-800VA)
The new Venus 2nd Gen provides emergency power in case of power outage and fully protects your system from spikes and surges.
See Venus UPS
SBP-TBF with Electronic Power Conditioner TBF™ (1000VA-1400VA)
The SBP-TBF UPS series eliminates line noise and provides battery back-up, surge protection, and automatic voltage regulation functionality.
See SBP-TBF UPS