The 2015 flagship HTC One M9 will also be available in 64 GB Variant apart from 32 GB one.

During this year Mobile World Congress [MWC 2015] HTC Corporation unveiled One M9 smartphone which came up with 32 GB internal version. Now the prominent HTC leakster has @LlabTooFeR has said that there will be 64 GB version too available.HTC One M9 Phone

Both Samsung and Apple has different variants of their flagship phones depending upon the internal storage capacity. For example the new Galaxy S6 comes in 32/64/128 GB and same goes with Galaxy S6 Edge and the iPhone 6 too.

Once again, rewinding you to the One M9 specs -

HTC One M9

Display:5-inch 1080x1920 Super LCD 3 display
2 GHz Qualcomm Snapdragon 810 processor
GPU:Adreno 430
Software: Android 5.0 Lollipop OS with Sense UI
Dual SIM: Yes
Main Camera: 20 MP rear camera with LED Flash
Front Camera: UltraPixel facing camera
Storage: 32GB Internal and 64 GB version
Connectivity:4G LTE, 3G HSPA, Bluetooth, WiFi tether, WiFi
Battery:2840 mAh Li-ion battery
GPS, FM Radio, 3.5 mm audio jack