Hi, In New Zealand we have 3 3G cell phone networks: 2degrees & Vodafone use 900MHz with 2100MHz infill. Spark uses 850MHz with 2100MHz infill. The European v3 modem supports 900MHz & 2100MHz while the US modem supports 850MHz & 1900MHz. I can confirm the European OVMS v3 does not work at all well on Spark's network in Auckland. It works well on 2degrees and I'm assuming also on Vodafone (but I haven't tested). The US OVMS v3 might work on Spark, but I don't know how many places Spark have holes in their 850MHz network that are filled by 2100MHz (possibly no such hole exists). The US model will probably also on Vodafone's 900MHz 2G network (which they say they are keeping up until 2025), but I haven't tested either of these. If you're in New Zealand, you might be able to get away with the US modem on Spark 3G or on Vodafone 2G. Otherwise you'll have to wait for the EU modem to be in stock again.