Replacement blades for Beiter Compound rests.
Tip widths come in three sizes

4mm - For small diameter arrows like Black eagle Revelation and Easton Protour
5mm - Same size as Trophy Taker narrow blades. Suits most arrows 
6mm - Wider for those shooting larger arrows like PS23 or indoor arrows.

Thickness determines the amount of spring in the blade.

Lighter arrow may benefit from a softer blade like the 0.20mm blade while a heavy arrow may prefer the 0.30mm blade.

The 0.25mm is a good "all round" blade