The NEW Magblock for Glocks MCL (Magazine Capacity Limiter). These limiters are pre-cut to fit the Glock 19 9mm 15 round magazine. This block fits into the follower and slides into the spring converting the magazine to hold only 10 rounds. Patented design offers Pre-molded levels to fit some other current 9mm and .40 Glock magazines. This requires some cutting. Does not affect reliability or magazine function. No increase in spring pressure which would reduce spring life. Compatible with the shown follower type only. This follower type is present on almost all metal lined Glock magazines. Can be used in Korean and original Glock magazines.