We reccomend to use specific thickness cover glass for microscopy because all objective are specially corrected for 1.5# cover glass type (corresponding to 0.17mm thickness of the glass):

• For confocal use 0.17mm±0.01mm. Like provided by Karl Hecht Assistent
• For STED you need high precission cover glass 0.17mm±0.005mm, ofter reffered at 1.5#H

If you have any questions regarding  choosing cover glasses for your experiments, please contact us.