Do NOT use any cleaner containing ammonia or alcohol, as they will cut into & or cause tiny cracks over time in plastic screen. HB says OK to use windex with vinegar, I have used Sparkle brand(purple jazz) window cleaner for years & it worked great. I always carried in boat some alcohol-Free electronic wipes similar to the little hand wipes some restaurants give U with rib dinners. Ones I like our by NICE'N CLEAN ELECTRONICS CLEANING WIPES for computer & TV monitors get em a Wally World bout 25 to a box in electronic/TV section-at ours U just have to look for them on shelf as people there don't know they sell them or what they for??????????????
Or U can buy a NAVPROTECTOR film that comes precut to size of U unit stays on by static, have one 997 going on 3rd season now works great & when people point to screen I don't worry bout them scratching it. Yep, it cost $25-$30 per sheet.-(Oh sheet pun?)