Philips Norelco HQ9 SpeedXL Replacement Heads

What is included in the box?

Does it mean that philips norelco 8240 xl is the same as hq 8240?. i'm sorry, but i need to be before i buy the philips norelco hq9 replacement heads

Does this include just the 3 blades or does it also include the head that holds the blades and snaps to the razor (as pictured)?

this box of hq9 says change every two years and has side box code hq9/50 where last hq9 i bought was hq9/52,says replace every year, what's the diff?