Price is for one battery

Genuine Joyetech 510/510-T batteries. 

These batteries are compatible with both the 510 and 510-T Electronic Cigarette Systems.

Manual Batteries are rated at a slightly lower capacity due to the space taken up inside the battery casing by the manual switch.  See full battery specs below.

Product Specs:

Standard Manual Batteries rated at 150mah

Length:  66mm

Weight:  9.5grams

Standard Auto Batteries rated at 220mah

Length: 66mm 

Weight: 10.5 grams

XL Manual Batteries rated at 280mah

Length:  91mm

Weight:  14.5grams

XL Auto Batteries rated at 340mah

Length:  91mm

Weight:  15.0grams

(All batteries are compatible with both 510 and 510-T, but some may be stamped with the 510-t logo)