While Sprint does not maintain a device list on their site detailing supported technology, one is maintained on Reddit ahowing just how small the voLTE list is: https://www.reddit.com/r/Sprint/wiki/deviceinfo
There is also the insane list of SIM card types for people bringing their own devices onto the network (not just physical size, the company couldn't standardize on sim card features for the network): https://s4gru.com/forums/topic/7833-the-s4gru-byod-sim-compa...
There is also the insane list of SIM card types for people bringing their own devices onto the network (not just physical size, the company couldn't standardize on sim card features for the network): https://s4gru.com/forums/topic/7833-the-s4gru-byod-sim-compa...