Meade Series 4000 #905 Variable Polarizing Filter (1.25") #07286. This purpose built Moon filter allows the user to easily decrease the image brightness for more comfortable viewing on the Moon. Includes two polarizer filters mounted in a special cell with finger adjustable slide control to vary light transmission from 5% to 25%.
The Moon at half phase or greater can be dazzlingly bright, especially through a larger telescope of 10” diameter or more, potentially making detailed observations an eye watering experience. This very handy item for the frequent Lunar observer makes the experience much more comfortable. The variable filter allows quick adjustment of the image brightness depending on the phase of the Moon and magnification in use by use of a sliding control.