This an awsome product!!!  I've seen these on ebay for a long time but was apprehensive about purchasing one because of the thinking that $cheap$ means cheaply made... well, I was wrong.  I saw one of these handguards on a fellow police officers m4 carbine and was very impressed.  The construction of the unit itself is extremely sturdy and the way that it attaches by sliding inside the delta ring and over the front handguard plate and tightening down via 4 hex screws makes it virtually unmovable and in my opinion almost sturdy enough to attach sights to.  Many other rail handguards are not ideal for mounting lasers, reddot sights, or flip up sights due to movement.  In my opionion this unit is 100 over 100.  You simply cannot go wrong for the price, it offers comparable quality at a quarter to a third the price as other well known brands.