| HKL Class M300 | |
| Interiorimage: | M300 espoo.jpg |
| Interiorimagealt: | Interior of a M300 carriage |
| Interiorcaption: | Interior of a M300 carriage |
| Manufacturer: | Construcciones y Auxiliar de Ferrocarriles (CAF) |
| Assembly: | Zaragoza, Spain |
| Yearconstruction: | 2014–2016, 2022 |
| Yearservice: | 2016 |
| Refurbishment: | 2021–2022 |
| Numberbuilt: | 25 units |
| Numberservice: | 25 units |
| Predecessor: | HKL Class M200 |
| Formation: | 4 cars |
| Fleetnumbers: | 301–325 |
| Capacity: | 576 in total, 228 seated |
| Operator: | Helsinki City Transport |
| Depots: | Roihupelto, Sammalvuori[1] |
| Lines: | Helsinki Metro M1, M2 |
| Trainlength: | 88.22frac=16NaNfrac=16 |
| Width: | 3.2frac=16NaNfrac=16 |
| Height: | 3.7frac=16NaNfrac=16 |
| Doors: | 3 sets of double doors per car |
| Wheeldiameter: | 850– (new–worn) |
| Maxspeed: | 80km/h |
| Traction Motors: | 12 × TSA TMR 50-20-4 230kW[2] |
| Poweroutput: | 2.76MW |
| Transmission: | 7.44 : 1 gear ratio[3] |
| Uicclass: | Bo′Bo′+Bo′Bo′+2′2′+Bo′Bo′ |
| Multipleworking: | Mechanically with all Helsinki Metro rolling stock |
| Gauge: | [4] |
The HKL Class M300 is a class of metro trains operated by Metropolitan Area Transport Ltd in use on the Helsinki Metro. 20 four-carriage trains were built between 2014 and 2016 by Construcciones y Auxiliar de Ferrocarriles for the Länsimetro extension.[5] [6] In November 2019, HKL announced the purchase of five additional trains, delivered in 2022.[7]
The M300 units were ordered in preparation for the automation of the metro, but this has been delayed until the early 2030s, the trains retaining their temporary cabs. The class was refreshed in 2021-2022, with the addition of air-conditioning and an updated driving desk.