The new cars added incorporate a number of interior design improvements, including higher seat backs and headrests on some seats. The sets are formed as follows. The M1 cars (5 and 9) are each fitted with two single-arm pantographs, and the M car (2) is fitted with one pantograph. The M1 cars (3 and 7) are each fitted with two single-arm pantographs, and the M car (9) is fitted with one pantograph. The M1 cars (3 and 7) are each fitted with two single-arm pantographs. Toyoko Line eight-car set 5122 received an all-over green vinyl wrapping livery in September 2017 to mark the 90th anniversary of the opening of the Toyoko Line and recreating the appearance of the original 5000 series EMUs nicknamed "green frog" which formerly operated on the line. It is scheduled to carry this livery until the end of August 2018. These are eight-car sets introduced on the Toyoko Line from April 2004. These sets are distinguished by a pink stripe above the doors. They are similar to the 5000 series, the only difference being that they have eight cars, and that they have the pink stripe instead of green. They are based at Motosumiyoshi Depot, and are capable of running through the Minatomirai Line. The 5050 series is notable as being the first type of train in the world to feature full-color LED destination indicators. One set, 5155, was scrapped in July 2017, following accident damage sustained in 2014. Toyoko Line eight-car sets are formed as follows. The M1 cars (3 and 7) are each fitted with two single-arm pantographs. J-TREC is testing a prototype car based on the "sustina" design, as part of a Toyoko Line 5050 series set. The car, numbered 5576, is part of set 5176. New 4000 series 10-car sets based on the 5050 series design were delivered from Tokyu Car from April 2011, entering service from September 2012 ahead of the start of Tokyu Toyoko Line and Tokyo Metro Fukutoshin Line inter-running services in March 2013. The ten-car sets are formed as follows. The M1 and M1' cars each have two single-arm pantographs, and the M car is fitted with one. Cars 4601 to 4604 (included in sets 4101 to 4104 respectively) were renumbered from former Denentoshi Line 5000 series cars 5469, 5473, 5474, and 5472 (from sets 5169, 5173, 5174, and 5172 respectively), and retain their original blue moquette seating.