Some specs as requested.
The blade is solid 1.5" diameter translucent acrylic. I was hoping my son would pick the cyan colored blade as most of the Lego Minifig sabers I have are that way. But he wanted the darker blue. I paid the extra money to get the polished material and have the ends polished after it was cut. Regular cast/etruded acrylic wouldn't light up as well without being polished.
The LED is a Seoul P4 white. It runs from a 4xAAA battery pack with Ni-MH cells. I initially tried a resistor to limit the current to 1000mA but the resistor got way to hot. So I am using a 1000mA buck convertor (not a Buck Puck but a different version). There really isn't an on off switch - I wired the recharge port to act as the on-off and use a dead (no wires) male plug to kill power to the saber. This helps keep the lines of the saber nicer. I had to make one concession to looks by adding a blade holding screw.
The entire optic package, battery pack and driver are a 'self contained' unit. It screws into the front end of the saber. I have the recharge port/kill in the pommel. They are connected with a couple miniature wire connectors. TO keep heat from the heatsink out of the battery pack I used a teflon spacer to keep them seperated.
Here is the driver board - and remember, that pack is 4 AAA cells (less than 1" square).