The Glock Compatible Mag Base Plate System allows you to attach multiple accessories such a clip, rail, as well as an enhanced base plate getting rid of the need to carry a Glock magazine holster. No more carrying Glock 17 magazine holders or holsters Immediately swap between the multiple included accessories Compatible with Glock 19 if using a Glock 17 (17 round or above) magazine Mag clip allows for multiple mag carrying options without the need for a pouch Available in multiple magazine calibers Glass reinforced polymer Weight - 10gr Remove existing magazine base plate Install the new supplied base plate Item Description MC17B Mag Clip base set includes 1 x G17 Mag base plate adapter 1 x Mag clip 1 x Base plate cover MC17SB 2 x Mag Clip base set includes 2 x G17 Mag base plate adapter 2 x Mag clip 2 x Base plate cover MC17SRB Mag Clip includes 2 x G17 Mag base plate adapter 2 x Mag clip 2 x Mag Picatinny rail 2 x Base plate cover