| E721 / SAT721 / AB900 series | |
|---|---|
 E721-0 series (right) and SAT721 series (left), August 2007 | |
| Manufacturer | Kawasaki Heavy Industries, Tokyu Car Corporation, J-TREC (Niitsu and Yokohama) |
| Replaced | 455 series, 417 series, 717 series, 719 series |
| Constructed | 2006– |
| Entered service | February 2007 |
| Number under construction | 36 vehicles (9 sets) |
| Number built | 146 vehicles (63 sets) |
| Number in service | 142 vehicles (61 sets) |
| Number scrapped | 4 vehicles (2 sets, tsunami damage) |
| Formation | 2/4 cars per set |
| Fleet numbers | P1–P44, P501–P504, P4-1–P4-19, SA101–SA103 |
| Operators | JR East Sendai Airport Transit (SAT721) Abukuma Express (AB900) |
| Depots | Sendai |
| Lines served | |
| Specifications | |
| Car body construction | Stainless steel |
| Car length | 20,000 mm (65 ft 7 in) |
| Width | 2,950 mm (9 ft 8 in) |
| Floor height | 950 mm (3 ft 1 in) |
| Doors | 3 pairs per side |
| Maximum speed | 120 km/h (75 mph) |
| Power output | 500 kW per motor |
| Electric system(s) | 20 kV AC (50 Hz) overhead catenary |
| Current collector(s) | Pantograph |
| Bogies | DT72 (motored), TR256 (trailer) |
| Safety system(s) | ATS-Ps |
| Multiple working | 701 series |
| Track gauge | 1,067 mm (3 ft 6 in) |
The E721 series (E721系) is an AC electric multiple unit (EMU) train type operated by East Japan Railway Company (JR East) on services in the Sendai area of Japan since February 2007.