12" Free Floating Handguard With Sectional Side/Bottom Rails (308 CAL) (Handguards) - $44.95

There are two options with a .308 receiver available high and low. The newer low profile handguard sits flush with a majority of newer .308 receiver on the market. The older DPMS receivers sits higher (high profile) and when attached to a low profile rail looks mix matched. If you attached a low profile (1/8") hand guard to a high profile receiver (3/16") the rail will not be flush and will step down at the handguard. Make sure you measure and know what you have especially if you are building your own .308

What do you mean by "low profile"?

Looks like a low profile rail. The website doesn't say, can someone confirm?