This is for TWO (2) a pair of these model PS-12350NB 

High-quality sealed lead acid (SLA) batteries from Power-Sonic provide excellent value for uses including computer UPS systems, alarm back-up, garden tractors, children’s vehicles, and many more. The PS-1235NB3 has a rated output of 12V, 35 Ah.

• Original Power Sonic PS-12350 12V 35AH SLA Battery.
• Dimensions: (L) 7.72 x (W) 5.14 x (H) 7.00. Weight: 24.70 lbs.
• SLA/AGM maintenance free, spill proof battery
• Rechargeable battery that can be mounted in any position, resists shocks and vibration
• 1 Year Warranty
• Sealed construction requires no maintenance
• Replaces all brands with similar specifications and dimensions