I just purchased a new Fox M+ bite alarm to use as a spare alarm for my friends and kids or as a back up to my Delkims. The company Fox is the big name in carp fishing in Europe. Fox makes top quality carp gear. I have two Fox M (old model) alarms that I have been using for at least 15 years. They are starting to go, but have served me well for a very long time.
This new model has the same general shape as the old model, but other than that, it has been completely redesigned. For starters, it takes two AAA batteries, a major upgrade over the pricey and hard to get N batteries that the old models ran on. The M+ boasts new battery saving internal circuitry, a new on/off switch in the front, and a redesigned screw in battery compartment. It has all kinds of waterproofing seals, and that's why these alarms will last 15 years even if you fish in the worst of weather. In addition, the alarm comes with a snap on case, a big plus that will protect the alarm when not in use.
The M+ bite alarms range in cost from about $45 to $55. Big Carp Tackle (www.bigcarptackle.com ) does sell them as do other online tackle dealers in the US and UK. If you are looking for a quality alarm at a decent price, consider the Fox M+. You will be impressed.