hello everyone, I have a question,, I'm relatively new to laser pointers....but I bought one through an acquaintance and likes it a toy,,I have a laser pointer model Gatling 21 cm this appears to have a plastic lens and problem is that at a long distance I don't have a dot but more of a rectangle ,,now I've read a few things on this forum ,,,but somewhat confusing,, So my question is ; which lens do you recommend for