Very good! The standard capacity of a modern, magnetic stainless pressure cooker, is 6 liters. Various models are produced from 2L to 10L.
The magnetic stainless models are induction capable. When I read the article it seemed to dispel the notion of a cellphone activated ignition. Cell phone functionality is less than ideal here, with a typical low quality connection. I picked a 6L pressure cooker from the cooking school for a test & we were unable to get a ring from a disposable phone sealed inside. I suspect a clever person could design an alternative.
I think that the cell phone idea is "over thinking" it. They have created a bomb in a sealed vessel, they know the event timing fairly accurately, so they used a cheap wrist watch with an alarm function as a timer and some batteries for ignition, and put all the parts into the kettle to become part of the shrapnel.
That way the perp(s) could prepare the devices 24 hours in advance and deploy them in the dead of night (after garbage pick-up of course), then get out of town and watch TV.
Boston could learn from NYC cops and get rid of all receptacles (garbage cans, mailboxes, &c) along the potential target zones. Or they could do as the French do in Paris and convert their "garbage cans" into hardened bomb containment vessels which direct the blast upward and away from street traffic.
Regards,
GtG
Cell signals are probably quite good in the area in question.
However, even if they used a cell phone, it might have simply been used as a timer, not as a means of remote control. In the 2004 Madrid train bombings, which killed 191 and injured a couple of thousand, that's what they did. There were several duds. In one case the cell phone alarm was 12 hours off. In another, the wires had come loose from the detonator. The police traced the SIM card from one of the phones to the perps.