Dear David,We need Customized optical filter quartz glass round disc to place in tool. 250 to 500 pcs each. 4 different colors purple green yellow/gold red size 31 mm 2 to 3 mm thick.lazer logo or engravedif you send me your email, i can send you pictures.Sincerely,greets Alainwww.ananda-bewustzijnscentrum.be Show More