I purchased one of these telescopes and almost immediately regreted it. The 4mm eyepiece that comes with it is completely useless fo anything but the absolute perfect viewing conditions. The conditions needed for this eyepiece to be useful are very rare. I would recommend that you not go smaller than 5mm for this telescope. The mount is garbage! The finder scope is junk as well. Celestron views this as an entry level telescope and has equiped it with pieces designed to prompt you to quickly replace them, preferably with their products. I have spent over $350 in improvements and I'm not done yet. The mount is extremely sloppy and unstable. The controls get in the way constantly when trying to view objects low on the horizon. The gears inside are very cheap and do not move smoothly. This makes it extremely difficult to locate objects using the Right Assention (RA) and Declination, (Dec) setting circles. Speaking of the setting circles, they are very crude. There is not enough detail to the degree markings on the circles. This forces you to guess at the settings and then search for the object that should be in your eyepiece. The finder scope mount is very loose, making adjustment an exercise in futility. There is almost 1/4" of play between the mount and the bolts that attach the finder scope mount to the telescope tube. The slightest bump puts you out of business, unless you can manage to re-set the finder scope in the dark. The cross-hairs inside the finder scope are invisible at night. Even if you have the finder scope perfectly aligned, at night you still have to guess where the center of the cross-hairs are at. Even if you manage to keep the finder scope from moving on you, you still have to align the finder scope to your telescope. The adjustment screws are not spring loaded and are also cheaply made. You are lucky indeed if you get it aligned properly. The focuser only accepts 1.25 inch eyepieces. This is great from the standpoint that 1.25 eyepieces are cheaper than 2 inch ones because it takes less glass to make the smaller ones. The disadvantage is that if you want eyepieces with wider fields of view, and trust me you will, you need a focuser that will accept both 1.25 and 2 inch eyepieces and accessories. Here is a link to an article I wish I had seen before buying the Celestron Powerseeker 114 EQ, or any other telescope for that matter.
PLEASE, read this article and do some research before you buy! Find the local astronomical society and go to their next meeting, send them an email, call the president of the club or better yet, attend their next "Star Party". It is the best way to find out what you like, and more importantly, what not to buy. This is especially important with eyepieces, (they can be the biggest part of your total investment). Here's a link to the astronomical society, where you can begin your search for your local club.
Take the advise of someone who found this out a bit too late. It is better to spend a bit more initially than to buy a cheap telescope and have to improve it almost immediately.