I've copy and pasted the relevent section from the EZY website. It covers m/bike helmets and duty free.
No weight restriction applies as long as you can place and retrieve the cabin bag safely in the overhead lockers without assistance
On busy flights you may be asked to place your guaranteed size cabin bag under the seat in front. Small items must always be placed underneath the seat in front for safety.
Your one ‘cabin bag’ covers a bag, laptop case, brief case, handbag, bumbag, rucksack, carrier bag or wedding dress carrier
Motorcycle helmets are also allowed as/within cabin baggage (providing they follow the relevant size dimensions).
Please note that all these items will be classed as your one cabin bag.
Our guaranteed size bag makes sure that customers keep essentials and valuables with them
We know that many customers want to make sure they keep essentials and valuables with them during the flight. Our challenge is that, as more people choose to fly with us, our cabin space becomes more limited. The guaranteed size bag promise helps us to offer customers the service they want, while managing pressure on cabin space and ensuring that flights continue to board as quickly and smoothly as possible.
Find out what items are allowed in the cabin in addition to your one cabin bag allowance
Other items you’re allowed in the cabin include: an overcoat, shawl, umbrella, crutches or walking frame/stick and one standard size bag of duty free goods from the departure airport. This is in addition to the one item allowance.
Infants travelling on an adults lap do not have a cabin bag allowance
Please make sure you carry any essential items for infants in your own cabin bag.
Arrive early at the gate to increase your chances of getting your cabin bag in the overhead locker
On busy flights not all cabin baggage will fit in the overhead locker. You stand a much better chance of putting your bag in the overhead locker if you arrive early at the gate. The gate closes 30 minutes before the scheduled departure of the flight.
Remember, the guaranteed bag size will always fit under the seat in front of you if there is no room in the overhead locker. On busy flights, if you’ve brought the maximum size bag your bag may have to go in the hold.
Cabin baggage will be checked for size with a baggage gauge at the bag-drop desk and at the boarding gateIf your one permitted cabin bag exceeds the maximum bag size, the Bag Drop desk will ask you to check the bag into the aircraft hold and a charge of £25 will apply.
If you go directly to the boarding gate and your one permitted cabin bag exceeds the maximum bag size rule, your item will be checked into the aircraft hold and a charge of £40.00 will apply.
To avoid these charges please make sure you understand the restrictions on cabin baggage before you fly.
From 2 July 2013, if you’re carrying one guaranteed size cabin bag, we’ll check this using the guaranteed size baggage gauge. If the bag is within the 50 x 40 x 20cm (including wheels, pockets and handles) guidelines, we guarantee the bag will travel with you either in the overhead locker or under the seat in front of you.
Liquids guidelines for cabin baggage: up to 10 x 100ml containers, stored in a clear, resealable plastic bag
You can carry liquidswithin your cabin baggage as long as they are stored in containers no bigger than 100ml and are carried in a clear, re-sealable plastic bag with maximum dimensions of 20 x 20cms. Each passenger can carry a maximum of 1000ml (e.g. 10 x 100ml). You’ll need to present your bag at security and you may be asked to dispose of liquids that do not meet these requirements.