The A-LINE™ LH-K1 Insertable Link Block allows the user to align the optical centers of 1/2-in. and 1-in. A-Line lens mounts. The Link Block has two 6-mm alignment holes spaced 0.25-in.(6.4-mm) apart to align the two sizes of lens mounts. It incorporates an 8-32 threaded mounting hole for post mounting on English SP and MSP Series posts. The slotted guide rod hole can also be used as an insertable post mount for guide-rod-mounted group of A-line lens mounts.