The devices we are testing are the effectively the launch device, bar the button mould which has been fixed to allow a bit more tolerance as that was reported in earlier testing, there are basically a few tiers of testing and batches, but in affect we are testing for a full 2 months before launch. I think there were around 800 units made up in this batch, then the batch following for actual launch arrives with any adjustments and things like accessories (mouth tips and adapter) that what will go on sale on the 15th, then we have stock for around 8 weeks while the next batch is made, this is the big batch , basically full production, and you want any issues or niggles ironed out by then, but there shouldn't be too many and any ones found should hopefully be small adjustments that can be made. That's what this testing is aimed at finding and stopping. It's basically a ramp up strategy to mitigate risks we don't foresee when devices are being used by a decent sized user base, and allows us to refine the device prior to full scale mass production, which is needed to make any profit on the deivce. We do also offer early access to existing customers if we think we have the units to do it, but it can go in and out of stock, and be a bit inconsistent, supply should be consistent from launch, and launch is basically the official date the whole business works towards.